Barrel Harmonics Testing - Part 1

[@WesternWilcats]

From how I understand this, the main effect on accuracy, assuming we have consistent timing for exit of the bullet out of the muzzle, is minimizing the effect of the high temperature, high velocity gasses behind the bullet exiting the muzzle on the bullet. This is also the reason muzzles are crowned, and all barrels are crowned. The suppressor results do make a lot of sense as this has the largest dispersion of the gasses behind the bulled and will prevent this from having any effect on the bullet after leaving the muzzle. Shooting multiple powder charges with each device (as you did with the suppressor in previous content as well as the beginning of this) does, reasonably well for a real world test, eliminate some of the variables with differing weights and configurations of the devices you have tested by giving a high probability that one of the loads tested will have the correct harmonics for the configuration. With consistent harmonics ( not necessarily powder charge) this would be a good way to observe how the gasses exiting the barrel would effect the path of the bullet, as these forces are the first thing that acts on the projectile outside of the (relatively) closed system inside the barrel. Just to say as well, I have been watching your channel for almost two years now, and as a young hand-loader, both in age and experience, and the information and honesty in your content is something that I look forward to every day. Thank you for the effort you put in to this, it does make many of our lives better for 10-60 minutes at a time!

[@jeremyhere2002]

I like your thinking about using a break with limb saver in tandem. The key to the limb saver is going to be where it ends up on the barrel. A very small move forward and backwards will change the harmonics. I've tuned barrel harmonics this way with airguns and subtle changes make huge differences downrange. Since you won't have a micrometer like on the Harrell break you'll have to find other ways to determine it's final location, especially if you ever have to remove it.

[@valbear438]

Been watching your videos for about a year. Sometimes I see a fly crawling on your target always find myself thinking do it dude shoot the fly.

[@SonoranAstro]

Inspirational.

[@daviddale3624]

Rule #1 for testing: "if it appears stupid, but it works, it isn't stupid"! The lump supports your weight theory. The adjustable Harrell's supports moving the bullet departure point to find the optimal distance. While all do not change departure fm your threads and perfectly cut target crown, they all have slighly different shapes and dimensions that affect the bullet as it transits the space inside the device. Which was the most comfortable to shoot of the best group producers?

[@Coyotethumper5]

Would like to see you slide that limbsaver up the barrel like an inch shoot it then another inch shoot etc using same ammo setup

[@Quality_Guru]

Absolutely loved the design of experiments. What a wonderful job you did. Obviously there is a direct correlation of weight to point of impact shift. I would love to see how the grouping would change by adding a secondary factor such as using the Limbsaver with the Silencerco flash h hider. Perhaps the addition of a second factorial would enhance the test results. I suspect that the Limbsaver device will need aditional movement to find the sweet spot.

[@ddexd]

Well I guess that means we need to reduce the number of variables a little. I have the material to make a 3/4 Lump, 1/2 Lump and a 1/4 Lump. Heck I'll even toss in a 1/2"-28 x 5/8"-24 thread adapter so you also test the Lump family on your .223. I'll try to get them made and mailed out by Monday.

[@JohnnysReloadingBench]

That would be awesome but it sure sounds like a lot of work. I'd be happy to buy these from you rather than continue to mooch. Time isn't cheap and I'm sure you'd much rather spend it on the range!

[@towaWPI]

I design experiments for a living and I agree. This set of shots tested a lot more than just the weight. How about just hanging regular weights off the top of the barrel? Might have to create a way to secure the hanging part to the barrel better. Maybe that can be machined?

[@ddexd]

Don't worry about the cost. I do machining as a hobby, and shoot for a hobby, and watch youtube as a hobby. So don't worry about it.

[@adeniranm7647]

Awesome! On behalf of the community, thanks Dave.

[@joechrisman8257]

Dave D thanks. Your a good fellow :-)

[@thejohnnybob]

Added weight will dampen vibrations, yes. The suppressor and the lump weigh the same, but the added weight on the end of the barrel has it's own moment as it relates to the mounting points of your receiver in the stock. That will lend towards the Shockwave Theory you mentioned in the beginning of the video as well as the physical weight and length of the barrel. As you know, a longer barrel generally produces better accuracy for the most part. The suppressor extends the pressure wave behind the bullet and tapers it off versus blasting it out behind the muzzle crown. I mentioned in your 223Rem video that the muzzle crown might not be uniform on the WOA barrel. Not necessarily messed up, but not perfectly uniform like a highly prepared bench rest rifle.

[@rochleeg22]

I wonder how the pressure wave would react in a flow through suppressor like a OSS. On my AR10 I went from a Battle comp to the lantac dragon my groups jump up by 1/2” or 3/4 of an inch pending on bullet weight.

[@wawheeler21]

Longer barrels are not more accurate. Usually shorter barrels are due to less harmonic whip.

[@kirkboswell2575]

Your hypothesis ISN'T garbage. It's quite sound, but your testing wasn't adequate. Harmonics are sine wave vibrations. And those waves will alter frequency and amplitude from one load to another, and one barrel to another. Simply adding weight to the end of the barrel is a sound start, but only a start. Change the weight, and you change the waves. Change the OAL and you change the wave. Your goal should be to have the bullet leave the muzzle at the same part of the wave each time. In other words, tune the barrel whipping to the individual load. Stiff heavy barrels were successful simply because the sine wave amplitude is very small - i.e. small whipping motions, and thus demonstrably more accurate. Browning's Boss was a move in the right direction, but wasn't as successful as it should have been because it was finicky to tune by the average person. But I think YOU should get one and explore it's possibilities. And I'd like to see you add some kind of length adjustment to your silencer to see if you can get even more accuracy using it.

[@macrocha5251]

Kirk Boswell really like your suggestion and agree with it... As we play with .01-.03 etc with out powder grains some of the devices you have used are compatible with those lines, the limbs aver, the thing with little holes and "dial nut" and the ones in the same line are just like our powder measure, you can play with them a bit more or less till you fine tune for your barrel harmonics/whipping. #johnny'sreloadingbench don't give up or consider yourself "confused" we all deal with things we don't know yet and learn sometimes take time and experience. I do LOVE your work, has been hard to hang around for a whole week waiting for your videos, it is TORTURE! LOL! Don't ignore the "muzzle breaks" but they are devices to tame the recoil even though they will tune your harmonics if in a weight close to the optimum barrel whip. God bless my friend, till best time... I really hope not long... Thank you again for the great work.

[@grahamparsons2610]

I had the opportunity to meet Ted Gaillard, a great barrel maker who happens to live close to my home growing up. He described barrel harmonics similar to the wave you mentioned. He said barrels whip or vibrate in a figure 8 or infinity pattern. Said the BOSS system was designed to have the bullet exit the barrel at the top or bottom or left or right edges of the 8 or infinity sign. At that point the barrel whip and muzzle was the slowest, and thus the bullet would land more consistently. So it’s not a function of weight per say, but more tuning the barrel vibration at it’s slowest point when the bullet is released from the barrel.

[@varietasVeritas]

The goal is to have the bullet leave the muzzle at the peak or valley of the wave. That is when it is moving the least.

[@StonyRC]

"The more I talk, the dumber I sound" - believe me Sir, that is the case for the VAST majority of individuals - it's not just you! In fact, I'd go so far as to say that the more you talk, the SMARTER you sound because you rationalise things carefully and "think out loud" - you don't just regurgitate other people's ideas. Experimentation is the key to learning. To my tiny brain, your results really do make sense: the mass of the object is one of several factors that help dampen or regulate barrel harmonics. Some of them (like the "three-pronged" flash hider or the rubber dampener are almost certainly oscillating themselves and by chance they are working in harmony with the barrel. A thoroughly fascinating series of experiments.

[@johnwilliams-gk1fb]

EC tuner is an amazing device and can be used with a brake

[@nells1776]

Something to consider for your hypothesis - I once read an article by Patrick Sweeney about the effect both barrel harmonics and exiting gas turbulence had on accuracy. While you don't want an erratic and unpredictability whippy barrel, he said the bigger contributor to accuracy was reducing the gas turbulence. I suspect this is why there isn't any direct correlation between accuracy and weight of the muzzle devices, but rather you are seeing the best accuracy from the devices which do best at reducing turbulence (i.e., the lightweight Silencerco flashhider). Based on your past accuracy tests, I'd say your Thompson Center has a fairly consistently harmonic barrel, so I think your hypothesis will be much less confused if you test various devices to see which ones do the best job of reducing turbulence to give you the best accuracy. Wilson Combat and Daniel Defense have a couple muzzle devices which come to mind.

[@Clarkecars]

I have been in love with my A-Bolt BOSS rifles in .308 and .300 WM for these very reasons for 25 years. Actually, the best results are making the barrel vibrate at the same frequency so the bullet exits the bore and crown at the same point of the vibration arc eaxh time for that bullet weight. S/F

[@anchorbait6662]

Wow. That's alot of info. Thanks for the epic. I'm still chewing on all those results. Can't wait to hear what everyone else is thinking

[@TALLA300CforumZ]

same here funny how stuff some times works out

[@4tango123]

The mental determination to solve problems. I give you an IQ of 160 . Congratulations an thanks.

[@eliinthewolverinestate6729]

Stocks vibrate against barrels. A big weight on end of barrel dampens the vibrations because it has to move more weight. It's why glassing beds and barrel springs work to cut down on vibrations.

[@TractorWrangler01]

Barrel tuning has been around for 100 years. We used to grind off the end of barrels and recrown them over and over untill we got a good tight pattern. the "shockwave" moved in a signwave type pattern and you have to time the exit of the bullet from the barrel at the sweet spot. Putting a supressor on a barrel may or may not change the group size. It depends on what the harmonics are changed to by putting the suppressor on. It could actually make it better. Lots of things effect accuracy.

[@mcofield2291]

Finally!!!! My wife waits all week to watch the Walking Dead when it's on. I wait to receive my notification bell that Johnny's Reloading Bench has a new video. Thank you for taking the time to conduct this test and hold down a full time job. Your the man Mr. Johnny. Have an awsome day sir.

[@eracer1111]

Thank you for editing out the mechanical nonsense. We don't need to watch you unscrew things, let the barrel cool, or cycle the bolt: Unlike a lot of KZbinrs, you understand that. Great video overall, and I look forward to watching more.

[@GravelGuerrilla]

I think the silencerco, with it's extended prongs, they acted as tuning forks, isolating a certain range(s) of frequency and possibly converting them to soundwaves, thus lowering the amplitude of that/those frequency(s) the prongs vibrate at. Same concept as the rubber limbsaver buffers

[@MrCharley201]

Looking forward to the Harrell's for farther testing.

[@AP2020_Outdoors]

I have prescribed to Chris Long, OBT, and using Quickloads to start my initial load development for several years now. Keep in mind that Chris conducted all of his test with no muzzle devices affixed to the barrel. From my understanding of the OBT Theory, it postulates that the BORE DIAMETER increases/decreases as the shock wave travels. So, in regards to a threaded muzzle device, the bore diameter will not change. However, the reflected wave will as it encounters the muzzle device. I am not sure of your intentions of shooting various powder weight charges. I think you should have held the powder weight CONSTANT. As you know, in science, keeping the variables down to ONE will help in finding answers! Your POI shift is due to NON-CONCENTRIC threads on your barrel. There is an error introduced when the suppressor is affixed to your muzzle. The groups tighten up, however, since the factory threads are not concentric with your rifle's bore, the POI occurs with the suppressor. Unless you let your pencil thin #1 contour factory barrel cool down, by the time you got to the 3rd 5-shot group, your test has now introduced a 2nd variable = your barrel's temperature = larger groups. The Harrel's tuner brake seemed inconclusive [maybe more testing is needed].

[@bvhnightmare]

In several of my precision rifles I have gone through several muzzle devices to see what shoots best. My loads never changed but the difference between different brakes is apparent. If it shoots well let it fly.

[@J9_j3]

most anticipated video on JRB i'e ever couldn't wait to watch

[@myongpark]

Hypothesis. The word that identifies actual science. Thank you Johnny.

[@jackasschicken5922]

Johnny, thanks for starting this. Like someone below said, it's weight and gas distribution that both affect the barrel and bullet. Since the silencer seems to help EVERY barrel, I think it's safe to say that the way a silencer reduces gas pressure as it exits and that that is the best way to keep projectile flight the same every shot. I'm planning on doing some similar testing. On uppers I put together myself, I plan on starting with barrel nut torque specs. Once I have the best group from torque, I will add the limb saver. Once I have that combined best group, I will try the various muzzle decices. I don't have a supressor, but I think that the brake style (hillman?) with the spiraled hole placement and adjustable weights might gain the best results due to the way it dispels gasses AND gives micro variants to weight displacement. Therefore, I am considering purchasing a brake light that to include in my own tests. Hopefully I can put together a video (might not be able to include actual shots like you do) and include at the minimum, showing just the results of each individual step. Thanks for sharing, you give me a lot of info to consider as I dive into this world. I look forward to part 2.

[@mmbadacid]

As with pretty much everything in shooting sports its a game of thousandths of inches and tenths of grains. Your test does a great job of showing muzzle devices impact accuracy period. I think you’ve also demonstrated that its not necessarily true that more is better. I think your testing shows that tuning with dampening or muzzle devices is going to be the same game we are already used to playing......very small increments. Grams vs ounces kinda small.

[@davidkoetting9099]

I have a Gamma 6.5 on my Grendel. It definitely tightened my groups up a 1/4". I also have a Pro Comp on a Voodoo Innovations/Adams Arms barrel that is amazingly accurate.

[@jimhans1]

David Koetting I agree, they both shoot well for me on various rifles, that was why I sent Johnny those 2 for this testing. Glad he is going to give the SF ProComp a second group!

[@jh5869]

Great work, Sir. Lots of data to filter through. I’ll need to watch this several times and see what jumps out. Thanks for all this hard work. We enjoyed having you stop by our chat last night.

[@J9_j3]

for me most surprising were effects from the limbsaver ring - by far lightest device yet created one of the most significant effects AND had least POI shift from POA (if at all). this is something to be said about the device. I wonder if larger limbsaver will produce even higher dampening effect on the barrel shock wave - that's what you should include in your next test. also, from where we stand at the end of this vid we can safely conclude that weight and weight alone to the end of the barrel is NOT a solution to tighter groups. it's more likely a circumstantial side-effect of having extra weight disrupting and altering barrel shock sine wave. we should step away from 'weigh as a reason' point of view and focus more on how to dampen those vibrations. obviously some of the devices has shown that dampening can be achieved w/o adding too much weight and i feel like that's were answer or one of the answers might lie.

[@pkf-phoenixkalaharifarming2672]

You get something called a EC tuner, it is made by erik cortina. It works the same as the tuneble muzzle brake exept that it sits behinde you muzzle brake. The tuning is something to understand, as the limbsaver, you can move it in 1/2” back on the barrel and see the deference. You can either tune a load to your rifle or your rifle to a load, say you shoot factor ammo you can tune the barrel to the right node.

[@captgringo]

I believe the forward position for the Limbsvr is only the starting point, the company suggests moving the device rearward in 1/2 inch increments , shooting groups between moves. This is a tuning process for that load in that particular barrel. These devices work quite well. Good luck in solving the problem.

[@hdmungeryt]

1. If you want to test with weight just for weights sake, you need to use a 'lump-like' system where the weight changes, but the effects of gas expansion and its effects on muzzle reaction are minimized/eliminated. 2. With regards to the variety of muzzle devices you have, the weight is the weight and the determining factors with regards to harmonics are a complete load development for each brake tested. (or a combination of that and the next paragraph) 3. When you start talking about adjustable harmonics devices (Harrell's and Limbsaver), you can just about tune any load to a rifle just by incremental testing of setting/position of the device to determine optimum setting/position. My understanding of these devices is that the range of adjustment required for bad to good to bad again (in a sine wave pattern) is not very big at all...maybe 1/8" to 1/4" or even 1/2" to completely define a 'node'. Going from one extreme of adjustment to the other will skip over MULTIPLE nodes and finding the center of a node over the total range is unlikely. Using your choice of non-adjustable brake and a harmonics tuner could be the best combination, with recoil management AND harmonics tuning. It would be nice if the Harrel's device could thread onto a muzzle with enough threads left to 'cap' its installation with a muzzle brake. But since it doesn't, a brake and Limbsaver combo might yeild the best results.Sorry for the long post...I had more to say, but I think I leave it at that.

[@bryanst.martin7134]

As fast as your bullet is, the sound velocity through steel is around 16,000 fps. After watching, I was impressed with the limb saver. Weight is obviously not the defining factor here, otherwise a bull barrel would be the obvious choice. Going back to the velocity of sound through steel, the explosion that launched the bullet sent an energy wave through the barrel. It will travel back and forth until all energy is dispersed. The barrel will reverberate not only in "to and from" motion but also in a circular/ radial pattern trying to dissipate the energy. This energy was near 30,000 psi, while much transferred to the projectile, the remainder transferred into barrel harmonics. The rubber has a tremendously different sound velocity, and it's low weight induces less "character" than the metal counterparts. So it absorbs some of the energy and returns a little less back to the barrel but at a delayed effect which causes interference and reducing the barrel oscillation with each pass of waves. Not a new concept, but a decent one for this application. Only draw back is heat. For the "aggressive" shooter, you may wind up with some smoldering rubber dripping from your barrel.

[@funigui]

Cross posted from /r/JRB: Okay finally got home from work and eagerly watched this video. What I am thinking is the amount of turbulance would have been much less on the ones that shot well. The Lump didn't touch the airflow, the Harrell's seems like it evenly on 360 degrees, and the limbsaver obviously did not touch the gasses. The hard brakes, like the M11 and the M4-72 seemed to open it up with the gasses being vented violently to the sides. I think that smooth gas flow plus the weight seems to be the key, like the lump. Now what about the suppressor? Maybe the gasses are just evenly dissapated inside.. Maybe?

[@stefanschug5490]

I find the most suitable powder that gives the lowest SD in the particular barrel and burns 100% before the projectile leaves the barrel. Then I play with the seating depth in .003" increments to hit a couple of nodes where your groups shrink significantly. Together with sorting the bullet by weight under the bell curve and using a mandrel for equalizing the necks of the shells I get the best accuracy for each of my barrels even without attachments which can be a real nuissance whilst hunting or carrying afield especially during sheep or goat hunting in the mountains. Sure any harmonizers and muzzle weights will flatten the oscillations of a barrel but if you do not hit a node in the vibrations you'll not getting the best accuracy that most barrels can achieve.

[@adamlong54]

The controlled gases affect the bullets stability and flight. I changed a muzzle flash that was spiraled like a twisted swirl. Then put on a dead air muzzle brake the results improved greatly . No more barrel whip jump nothing. Flat and I don't have any scope picture lose or moving. The swirling flash or break every time lost scope and target had to be required each shot. Also crowned the barrel before the changes smoothing out gases makes big accuracy gains. I have also used the limb saver rubber barrel it works good you have to move it to find the sweet spot little by little bit does help

[@TractorWrangler01]

The answer to your last question is that all of them give the barrel different barrel harmonics. Playing with that adjustable one will make you a happy camper. Harmonics have to be adjusted in small incraments.

[@BernieDiaz]

I'm watching this video 2 years after you made it because I just ordered the Harrell's Tuner adjustable break. I have exactly the same T/C Compass rifle in 6.5CM with a Silencer Hybrid can which I bought with several accessories including the flash hider you tested. It blew my mind! I need to understand too what's going on. I'm just about to watch parts 2, 3 & 4. I'll be back!

[@DougMacRay]

You had my Thumbs Up at "The more I talk the dumber I sound." You just nailed the description of a number of the recreational shooters (and golfers coincidentally) I meet. There's a lot of opportunity for socialization in these two wonderful sports but unfortunately, these interactions often become a platform for the self-proclaimed experts to exploit their agendas. Whether it be equipment, technique or politics, if I want your opinion, I'll ask you. Or, I'll watch a video like this one here. Great content here.... and great advice to go with it. Thank you. Stay Strong & Stay Safe, Boston

[@markjar]

After watching the video, the differences in grouping could also be attributed to the way the gas is redirected with the various muzzle brakes. What got me thinking about this was the group of the surefire brake. It doesn't offer horizontal gas ports like the m11, rather its more of a 360 degree much like the harrell's brake. What deviates is the gamma brake, but maybe the angled gas ports help to steady the barrel while the bullet is travelling through it. Also the limbsaver through its rubber properties probably helps to dampen the vibrations at the end of the barrel (notice it kept a very close zero assuming you zeroed the tc compass without anything on). Limbsaver combos with the other brakes would be really interesting to see! Thank you again for taking the time to create this content!

[@fatboy20010fatboy]

I think you hit the nail on the head with the adjustable.. problem is they're waves you can't see..when you adjust along a linear path, you have sine waves with harmonic highs and lows..so as you turn the tuner dial up and down, you attempt to balance those harmonic waves of distortion..there maybe several choices but it is up to you to find the sweet spot and it takes time and diligence... You've taken on a monster of a subject .. these devices are not plug and play tuners as you know?.. every barrel is different and requires individual tuning ( small incremental increases or decreases) and range time... I wouldn't get frustrated..You could write a book on the subject.. attempting to condense it should be broken up into segments so you can take a deeper dive into how and why each one works the way they do ..pro's and con's? Keep up the good work and keep hammering 🔨 the paper!

[@Millennial_marksman]

Love this channel. Best thing to watch when staring at the bench and contemplating loads/setup/etc.

[@w740lp8]

Powder charge changes barrel harmonic. I run a Ryan Peirce muzzle break I was running 42.2 grains of h4350 before the break. After I added the break my groups got worse. I am now running 40.9 grains of the same powder and am shooting .30 groups at 200 yards. Good luck

[@shakes00lude]

I'd love to see you play a snippet from the POTUS song Lump every time you bring out the lump.

[@axelsprangare2579]

Really good video Johnny! You helped me alot for choosing a tuner for my future 6.5 sherman max build. Thanks!

[@craig243ful]

I love how you use science to figure out what is really going on keep up the good work

[@spyderxtra777]

From my feeble understanding, and from what I just saw.... I reason that The barrel is like a guitar string, you want it to vibrate “just right” and “play the correct note” for accuracy, the weight as well as the shape/design chambers in the brake/how far they are spaced/how thick the metal is etc could influence how it vibrates, heck, the physical length of the device and the overall length of the barrel with the device could be a major factor in how it vibrates. A longer string plays a lower note etc.

[@luissandoval4093]

Wow, very very interesting.. Besides being an airgunner, long range shooter, I also shoot target archery. I mention this because the vibration in the bow (specially the string), considerably affects the arrow fligt. Some people say that barrel harmonics do not affect the bullet since the vibration occurs after the bullet leaves the barrel. Nothing more wrong... I agree with some comments about the drag forces that occur after the bullet leaves the barrel. So one possibility could be that the devices change that right outiside the barrel. The CON to this hypotheis is the limbsaver in the 2 positions exposed in the video. (still thinking about this Congrat´s for this effort!

[@AnthonysOutdoors]

The bullet is leaving muzzle in less turbulent air with the suppressor on. Watch high speed footage of bullets leaving muzzles and you will see that gas actually exits before the bullet does causing the variations you are seeing. Putting a suppressor on slows the gasses down and allows the bullet to exit before the gas.

[@ExpatriotSilencers]

You are on the right track but misunderstand whats occurring. The propellant gases are travelling much faster than the bullet they are pushing. As soon as the bullet leaves the muzzle, those gases accelerate past the bullet and give it a kick in the ass. This is why a concentric and good condition crown is so important to accuracy. A damaged crown causes uneven gas flow out of the muzzle which gives the bullet an uneven kick in the butt. That causes the bullet to yaw, which causes a loss of accuracy. A suppressor is a very efficient way of stripping the high velocity propellant away from the bullet and reducing the kick and resulting yaw the bullet undergoes. All of which results in increased accuracy.

[@SOLDTONORM]

Overall weights vs center of gravity position relative to the end of the barrel. The research I saw from the UK involved movement of a millimeter at a time.

[@klevee6076]

The suppressor is reducing the oscillations,in the same way a heavier gun has less felt recoil. And the compass is a great rifle. My brother has one in 22-250 which prints the cheapest federal blue box at just over moa and reloads tuned for a heavy barreled savage print sub moa consistently. From a skinny barreled hunting rifle that's impressive for sure.

[@adeniranm7647]

Man, this hobby can definitely be frustrating! Can't wait for part 2. Keep your head up and keep the testing going. The more data we get, the better we can move toward a reasonable solution.

[@PilotMcbride]

You leave us with this lot and "hope" we'll join you for part 2? HAHAHAHA!!!! We got no choice mate, lmao!! You've left us hanging exactly the same as you. Of course we'll be watching!! A couple of things that you can try if you like, you shot 5 round groups. The first thing is to measure you best 3 shots of each group and compare them. The next thing, pick the mean POI for each test and measure the the best 3 shot groups for each attachment and see which correlates best to the open 5 shot groups. You are conducting excellent tests, and they've been bloody brilliant to watch! Thank you for the work you do, absolutely brilliant! Cheers from down under :)

[@kirkboswell2575]

Pilot McBride - I agree with you on the shot groups. Do 3 shot groups to find the set ups that warrant further testing and/or refining. That would be an excellent way to pare things down a bit, and use 5 shot groups to test those selections. Yes.

[@ClaytonMacleod]

I suggest you google “Purdy prescription” and have a read. If you understand that, you will understand why your groups usually get noticeably better with the can screwed on. It is the same reason a barrel tuner works. Mr. Purdy developed this theory with regard to subsonic rimfire shooting in mind. I’d need to read again myself to refresh my memory as to how this might need to be modified to apply to supersonic centerfire shooting. But with the rimfire stuff the idea is that a barrel is a tube closed at one end like a pipe in a pipe organ and it needs to be tuned so a node of a wave of the odd harmonics is at the crown. And the barrel tuner is set to lengthen the barrel beyond the crown by a certain amount in order to put one of the odd harmonic nodes at the crown. There is even a spreadsheet to make this calculation extremely simple. And the calculation has been confirmed by many different people around the world in relation to their trial and error tuner settings. Confirmation after confirmation that the calculated value was within a few clicks of their trial and error tuner position, and likely differed simply because of measurement error for the calculation method. It even shows how to apply the method to tuning the barrel without a tuner attachment by instead counterboring the muzzle so the crown is down inside the barrel by the calculated amount. It is an incredible idea and more than worth your time to investigate. Weight is not involved at all. Only sound waves and harmonics inside a tube that is closed at one end.

[@tilley3rar]

1) Notice you said without a muzzle device it groups up to 1.5in. All but 1 device was an improvement on that. Perhaps because any extra material absorbs some of the shock wave. 2) The ammunition needs to change to suit the brake and place the "accuracy node" at the tip of the barrel. Theoretically the most "accurate" brake for your rifle is the one that just happens to place that node at the crown or absorb so much harmonic shock wave with mass that movement is negligible. It's just theory to me but someone else may have tested it.

[@michaelenochs4033]

My best educated guess is this: I just started learning about barrel harmonics and my brain is working over time. I play guitar. I record guitar. I just watched another video about barrel harmonics and I learned two things: There is a frequency that happens in the barrel, and the bullet leaves the barrel before we see any motion in the barrel when a round goes off. Hang with me here because I have to explain myself before getting to the goods. Just like in another video, I'm going to use the guitar as an example because I actually do play guitar and I've taken 2 years of music theory and 4 years of choir, just don't make me sing cause that's why I play guitar. From music theory, I learned about a word called timbre, pronounced tam-ber: the character or quality of a musical sound or voice as distinct from its pitch and intensity. What this means is literally everything that can produce a vibration is a form of timbre. If you take a pencil and tap it on a desk, that noise you hear is a distinct pitch and intensity "timbre". Alright so why is this important? Well, when your rifle goes bang, there is an incredible amount of distinct pitch and incredible intensity forming a crazy high vibration. Your barrel would be like the desk in my example with the cartridge being the pencil, thus creating a freak-timbre-of-nature. Here's the thing, if the bullet leaves the barrel before this vibration in the barrel goes off, then what happens? I believe this theory is wrong and here's why. The speed of sound, according to Google, in feet per second is 1,125fps in ideal conditions but I'm not going to get into specifics. 1,125fps is the speed of sound. Do you know how fast the speed of sound is........... through a solid? It's 19,685fps or 6,000meters per second!!!!! Wanna know what's even more mind boggling?! According to my Hornady Reload Manual, a 140gn BTHP at 38 grains of IMR 4451 is 2500fps! That means you can multiply the speed of sound to Mach 2! Now we're looking at the speed of sound in the 40,000fps range in a solid material. Okay let's put away the math book and get back to it. There is no way your bullet is leaving before the vibration of this blast goes off. This is barrel harmonics. This is what's happening inside your barrel. Let's go back to the guitar for a second. You ever watch a guitar string in slow motion after it's been plucked? You can literally see the frequency at which it resonates. Your barrel does the same thing except the frequency is so fast that it's too fast for your barrel to mimick for it's size. If you look at a high E string on a guitar, not the low sounding one, you can hardly see it moving because the frequency is too fast, hence why it sounds higher in pitch. But when vibrations start to settle inside your barrel, that's when you notice the barrel flexing. It's because the frequency is slowing down, the pitch is getting lower. The reason the rubber Limb Saver worked is because it helps soak up these pre-vibrations prior to your bullet leaving, which in turn, leaves your bullet alone, giving you better groups. Can you imagine what would happen if you made a barrel with a checkerboard metal/rubber design?! I'm not sure how you could do it with the rubber being it's weakest link, but it could be insane. Gosh I have so much more to say but I'll leave it at this. It's my best guess 🤷 Oh yeah, the other muzzle devices are changing because you're messing with the timbre. The frequency inside the barrel is changing. Okay, I'm sorry, I have to mention something. Going back to the guitar, if you played an open string, we'll say the low E string, it sounds low. If you cut the string in half from the nut to the bridge, you'll be exactly at the 12th fret which is half of the fretboard. This 12th fret is the octave, it's the same note one octave higher and the vibrations are sped up twice the speed. If you keep your finger on the 12th fret and cut the string in half again, you get the 24th fret and again, it's another E note. If you continue cutting this in half, you'll run into E notes to infinity. Fun fact: If you know what pinch harmonics on a guitar is, you literally pinch the string with your finger and pick and you get an incredibly high note, all over the string near the picking hand. These are harmonics. Your barrel is similar to the entire length of the E string if we didn't put frets on your rifle. When you change out the muzzle devices, you're messing with the density and length of the barrel, timbre. You're messing with the frequencies inside the metal of the barrel. Now I'm not sure if this is true, but if the transient waveform is at its max peak, the crest, the highest the wave will go, right when your bullet is leaving, you're going to get poor groups. But see I'm not sure if that's even true because the frequency is so high that the waveform would probably vibrate several times at the very moment the bullet leaves. Not sure if I believe this. Something that I do believe in is the length of the barrel and the timbre phenomenon. I am 100% positive something else is happening but I can't explain it or else I really would write part 2 of this novel.

[@nstied]

Consider a sound wave propagating through the barrel. Different weights of device may interact with the peaks and troughs of that wave differently. Some weights are going to damp the wave, others might even add to it by causing resonance. If this hypothesis is correct, it would make sense that the group sizes oscillate as you reduce weight. I think it would be interesting to plot the muzzle device weight vs the group size. I might actually do that. This test might even allow you to determine your barrel's waveform with this load. Freaking cool! I am just a lowly geologist, but I do have some background in geophysics, and found this fascinating!

[@milonjano]

The end mass is absorbing the frequency energy. the limb safer is also absorbing energy by transfer of energy mostly the same. I use the limb saver on my 22lr target rifles.

[@neilharris4462]

Harrells at 0, 50, 100, 150 settings would be a great place to start and see if anything starts to make sense.

[@johnmichelini4841]

Hi, how much doe the sliding weights on the Harrells weigh?

[@michaelgauger2306]

Use the Harrel Barrel Tuner again! However, not always adjust a whole revolution, but always two tenths of revolution further per shot passage. The shot group opens and pulls back together! That repeats the further you adjust.

[@jfor0948]

The heavy barrels will also have a large effect in controlling consistent temperatures due to the higher thermal mass absorbing the heat. The grain structure in the metal will also effect the thermal expansion of the barrel. For example the Benelli Cryo barrels, the pattern is much more uniform than with standard barrels I've used due to the Cryo "tempering" normalizing the grain structure.

[@leonhart2452]

On the Harrels and Limb Saver, follow the instructions on adjustment. Tune them to tightest group.

[@alannagel4381]

Think of the end of the device as a shock wave reflector. Anything that breaks up the radial or longitudinal components of the wave into multiple smaller reflected waves will diminish the standing wave that sets up in the barrel. I believe that the light pronged flash hider was effective because it produced at the least two reflections. The first was from the muzzle flash hider interface and the second was a delayed reflection from the tip of the prongs. The resulting fuzzy reflected wave less likely to build into a single strong wave. Remember the waves make multiple trips up and down the length of the barrel before the round leaves.

[@joelclark2130]

Wow what a great video two thumbs up. Just throwing it out there some of what you saw has to do with Barrel vibration harmonics, and each device's ability to absorb and reverberate harmonics. It has to do with the ability to cycle and recycle Shockwave length. I am also currently working and planning to build my own Barrel device it has to do with the ability to extract the vibration from the Barrel

[@silentbob267]

Weight is important but you also need to take the overall length of the barrel and muzzle device into consideration when dealing with barrel harmonics because the waves travel back and forth down the length of the barrel. Any change in length changes the distance the waves have to travel and will affect the results even if the weight is kept the same.

[@tomwaldner9299]

If you're thinking that weight makes the difference ask the guy who made the lump make you different lumps that match the weight of those other devices. I would have to think that the ports on those devices being of different sizes would effect your bullets pointof impact.

[@cacinaz8802]

Maybe you solved this a while back since you did this test in 2018 and its already 2021. It occurred to me that the barrel vibrates in a sine wave that oscillates above and below 0 along the x-axis - actually down the barrel toward the muzzle and back a few times before the bullet actually leaves the barrel. I think its not a function of weight but of length. Your suppressor is twice as long as any of the other brakes, tuners you tested. It could be that the length of the suppressor is such that the bullet leaves the barrel when the wave crosses the muzzle, thereby maximizing accuracy. Just my two cents.

[@czechnolike]

Awesome! Going to try one of these with my AR-15 24 inch bull barrell

[@Do-UR-Research2749]

Its a combination of the amount of weight and the location of where that weight is placed. It's doesn't take much movement to make a difference. You will find that on most tuners you'll find a good spot within a turn.

[@glock17games]

I think there are 2 things going on. first the weight that can have influence on vibrations (where you put the weight also alters the tune, kinda like playing a guitar. Secondly, how the bullet leaves the barrel is also influenced by how the gasses are coming out behind and around the bullet. Take a look at something like a Walther match air rifle. The barrels are only about 2/3 the length of the barreljackets, that other 1/3 is used to stabilise the air as the pellet leaves the barrel. Now add to that, that usealy cheaper made barrels prefer to have some tension on them (like something pulling them down) and i think you have your answer.

[@49Wildman]

I think you are throwing in to many variables. 1. each break is different by the design and the way it'll effect the movement of the rifle. 2. Each break has a different profile of a crown which interact with the sonic shock wave of projectile leaving the muzzle. 3. Length of the muzzle devices can take a small roll in performance 4. the clearance of the of the projectiles passing the device. To me the most controlled muzzle device you have is the lump. I think for test the harmonics of the barrel. I think you should get a control lump turned to a light weight device with multiple weights in between to the heavys weight you would like to test too. with a standard degree target crown.

[@Pest789]

Maybe do a chart showing weight on one axis and group size on the other axis. Changing the weight changes barrel harmonics. Maybe there are bands of weight ranges that cause the muzzle to be centered better as the bullet leaves the barrel. Your summary graphic seemed like it might be showing that, but it's not clear because the spacing isn't linear by actual weight. The limb saver in the middle of the barrel should be thrown out of that chart because it's not near the muzzle like the rest. It'd be really nice if there was a device that could be tuned by changing weights

[@sethaddison2039]

What were the length of all those? Every flash hider, comp, etc will change the overall length(and weight) of the barrel and affect the timing of it. That's why the group changed with the "lump" in 2 positions. The weight didn't change, but the barrel got longer. If you read the opt barrel time paper, they have the excel spreadsheet you can download and it will predict the best modes by length. If you look in your quick load program, it has the barrel time in the ballistics. From my experience it's usually pretty close...

[@hornet224]

Basically, you want to shoot from a dead barrel, such as a cannon with a rifle bore. Then there will be little or no barrel harmonics to distort the trajectory of the bullet. Theoretically, the axis of the bore is true and stable and the bullet exits the muzzle at the neutral axis. That what you want your muzzle device to do.

[@harleyeckles]

Before highly tunable PCP airguns became popular, Field Target airgun shooters used air-strippers on their barrels to redirect the air pressure turbulence from disrupting the stability of the pellet as it exited the barrel. Later, as airguns became more tunable, with adjustable regulators and adjustable hammers, shooters were able to tune their guns so there was little or no excessive high pressure air following the pellet out of the barrel. I think it is possible your suppressor is acting as a closed air stripper.

[@livingintheLight.]

I put one of the limbsavers inside the 15" handguard on a 16" Wilson barrel 358win with a target crown and it shoots amazing

[@WestDesertShooter]

So damn interesting! So the thing I notice is 6/7 devices are not the traditional side port brakes. This gun seems to like not having side port brakes. The flash hider isn’t and the harrels has small holes all around. That’s about all I’ve got. Maybe the one ported brake used was a good eight that the barrel liked? Haha it’s fun to think about!

[@JohnnysReloadingBench]

I can't believe how much difference all this makes. Tunable brakes should be a whole lot more common than they are!

[@sindeecharlton8857]

depends where you place then on the Barrel. Take the limb saver and try different locations like with in 5mm movements. sink it to the harmonics of the barrel.

[@craiganderson3170]

I watched the series, then screwed a NAPA fuel filter with no guts onto my Ruger American .22lr and my groups shrunk. Thanks for the confusion. Update: today I adjusted the action screw from 10 inch lbs to 50 in lbs in increments of 5. This was just as dramatic as the muzzle devices. then I found the best tightness and then screwed the filter back on. I am getting dramaticly better groups at 50 yards. testing the limbsaver tomorrow.

[@ReconMan772]

The limb saver does work .. I like to start at the stock and move it forward 1/2" .. Then you will find the sweet spot .. Turns factory loads to .50 groups in most cases

[@SOLDTONORM]

To further mess with your mind...it occurs to me that the harmonics may not be a 2 dimensional wave, but rather a spiral induced by barrel twist. The harmonic will outrun the bullet to the end of the barrel.

[@yunggolem4687]

It's accurately a figure 8 pattern from a perspective close to in-line with the barrel, not the side perspetive. You can see it in slow motion footage and is very dramatic on long barrels shooting large calibers.

[@ssswdon]

With the Thompson I think what you need is a floated barrel, cheap stocks cause unstable and Inconsistent groups. I encounted this with my how until I put a x-ray stock and now I am sub 1/2 moa at 100yds

[@timturner7609]

32:13 they aren't brakes. The brakes basically are stretching the barrel. The recoil wants the barrel to move backwards but the brake wants the barrel to move forwards. That jolt of the brake pulling the barrel forwards is going to add extra harmonics to the whole situation.

[@yowser8780]

Yes... barrel vibrations are the key to good groups. That was pretty much proven on the Browning 'muzzle break' device they had for awhile. The TC rifle has a pretty light barrel. Simple device like the Limbsaver might be it for that rifle. I'm watching your finger on the trigger... seems like you have a lot of movement there. (?) Trigger is jumping up 'a lot' on the finger once it fires. (?)

[@vlambaigo]

You have done some serious scientific work here. Besides looking at barrel dampening, the weight on the muzzle can in my experience be accounted to muzzle up pressure with weight added to the front end of the barrel. Maybe you can show us some real results by taking into account the pressure applied by the muzzle gas when the muzzle gas escapes the suppressor/muzzle break. this should also affect the muzzle position/point during the period that the bullet exits the muzzle. I guess all of this is a science after all, and such the best grouping was given by the devices with either the highest weight or an evenly distributed gas distribution. I will definitely be watching the trailing videos for more info.

[@Prepare2Survive]

I was trying to enter in your load data into quickload so I could see the barrel timing for the TC compass, but quickload doesn't list imr 4451 powder in the program.

[@702HOLLA]

That limbsaver balanced out the harmonics and the exit of the bullet it looks like RealGood🤙

[@shannonnunn]

You want to know what it is..... It is the reduction and the homogenizing of the pressure as the bullet leaves the barrel..... A silencer reduces the amount of pressure leaving the barrel with the bullet..... Different powders burn at different rates and the most consistent loads on average come from loads with reduced muzzle pressure where the powder burn is already totally complete and the pressure spike is on the way down.... If you look at quick load it will tell you the amount of powder burnt by the end of a specific length of barrel with a specific charge.... Barrels have harmonics as well as muzzle pressure effects on bullet exit consistency..... For heavy bullets you can usually push them faster with a slower burning powder but the muzzle pressure will be higher which will introduce more randomness to a bullets muzzle exit.... You want the bullet to be asleep by the time it leaves the barrel.... It will even make a different sound as it exits a barrel.... Long barrels don't only allow the maximum velocity for a cartridge they also reduce the muzzle pressure.... My gunsmith builds my barrels around a specific load and bullet and makes my barrel as long as I need it to be to reduce muzzle pressure.... Thicker barrels also reduce barrel whip and improve harmonics.... The nodes that you find with a target barrel are much more forgiving when it comes to changes in temp, powder charges or the smaller inconsistencies found in handloads.... Also making sure your rounds are concentric improves accuracy by leaps and bounds.... It is the only way to find the true nodes and es's of different charge weights.... Silencers have the same effect of reducing muzzle pressure

[@saltcreekammo]

Between the limb saver and the tuner brake, you should be able to shoot sub .25” groups.

[@macrocha5251]

As i posted on Kirk Boswell comment down the answers… "As we play with .01-.03 etc with out powder grains some of the devices you have used are compatible with those lines, the limbs aver, the thing with little holes and "dial nut" and the ones in the same line are just like our powder measure, you can play with them a bit more or less till you fine tune for your barrel harmonics/whipping. #johnny sreloadingbench don't give up or consider yourself "confused" we all deal with things we don't know yet and learn sometimes take time and experience. I do LOVE your work, has been hard to hang around for a whole week waiting for your videos, it is TORTURE! LOL! Don't ignore the "muzzle breaks" but they are devices to tame the recoil even though they will tune your harmonics if in a weight close to the optimum barrel whip. God bless my friend, till best time... I really hope not long... Thank you again for the great work."

[@KK40384]

So the 6.5 specific muzzle devices shot better than the 7.62 ones. Here’s my personal experiences and theory on this. Specifically with the Gamma brake, on my Gendel I ran the 7.62 gamma prior to the 6.5 being available and it shot OK with factory ammo. When the 6.5 became available I switched and my groups shrank in half almost. Why is that? My theory is that the brake is designed to divert gasses to reduce felt recoil. Shooting a 6.5 diameter bullet through a 7.62 specific brake allows gasses to follow the bullet through the larger bore of the brake possibly causing turbulence and destabilizing the bullet slightly. The 6.5 brake with the tighter bore does not allow for that, or as much. Just my theory and I can’t really prove it other than to to shoot groups much like you did and show the results.

[@drobbyb]

Johnny I have a theory: Noticing how the 30 caliber muzzle devices printed in relation to the 6.5 devices and the silencerco flash hider (discounting the limbsaver variable) and accounting for the performance of the suppressor, I think you are battling gas pressure. What I mean by that is once the bullet reaches the end of the barrel, the pressure normally spreads out in all directions in the shape of the crown in the case of a bare barrel. With a suppressor the pressure is diminished greatly and it's effect on bullet trajectory in minimal once the bullet exits the suppressor. In the case of the 6.5 muzzle devices the bullet has a tighter fit and the gas takes the path of least resistance reducing it's effect on bullet trajectory once it leaves the barrel/muzzle device. In the case of the flash hider, it's acting more like an extended crown except the gas pressure in directed in three equal directions. As for the 30 caliber muzzle devices there is too much space and too much gas blowby and it's effecting bullet trajectory. I don't know if that's totally correct, but it's my theory.

[@BTCAsia]

While I have no idea what “it” is, clearly there is a factor here significantly affecting precision. The near-weightless rubber boot change, just moving from muzzle to mid-barrel, suggests the change is not necessarily weight related, but is definitely a variable we need to control if we are to have any hope of achieving precision with our rifles.

[@heywire101]

The limb saver is tuneable like the Harold's start 1/4" from the muzzle and shoot groups sliding it back 1/8" at a time. Something to think about when you test the Harold's.

[@Gunner-73]

I test is good I think. Understanding the answers are the question. Lets say to ring a bell. To stop the bell from ringing, touch it, where you touch it and with how much weight or force determines how fast it stops ringing. As with the thick barrel, the shock or sound wave is smaller so the distortion is smaller, kind like a snare drum or thin metal, you can almost see the vibration in the disk. If you bleed of that vibration like a suppressor, distortion is minimized. I like the idea of attaching a weighted object to the barrel and test that. Just my thoughts

[@pawswet9476]

To show what is possible with harmonic tuning, cut the number of variables to one. Small changes, on the order of a millimeter, on the Harrell’s brake would be fascinating to see. For the Limbsaver, 1/16” at a time. Testing the limbsaver with another device is too many variables! The Funshoot video armorer was getting results with one hour (clock face) of rotation with different shim thicknesses on an A1 flash device. Those are small steps, just like charge weights. Great video series..thank you!

[@GetMeThere1]

First, let me compliment ALL your videos. They're ALWAYS great. On this topic, though, I think I'd start by asking a more fundamental question: Given the inevitable velocity variations from shot to shot, could we assume that it would be IMPOSSIBLE to expect bullets to exit the barrel "at the same point" in a harmonic vibration each time? I'm incited to ask this question after watching other videos touting the fantastic accuracy of new cartridges (in particular, 300 Norma mag and 338 norma mag) due to their design. In fact they talk about velocity SD of about 3 fps -- and, around a well chosen powder weight, that consistency stays EVEN WHEN CHARGE WEIGHT varies by 0.1 grain or so between rounds! Shooters of those cartridges are very interested in ultra long range, and for that you need very close velocities or else long range groups will string vertically to quite a large extent.

[@mattone7458]

Stacking the limbsaver with the harrels device , suppressor, or one of the better performing breaks might be a cool video?

[@mmbadacid]

Since your tests have shown that muzzle devices clearly impact accuracy and can make or break a barrel. Maybe bring out that ar10 barrel that “wouldn’t shoot” and got shelved and see if any of your assortment of muzzle devices will turn it into a shooter. After watching this series so far i’m more inclined to try some different devices before punting on a barrel that “doesn’t shoot”.