Testing loaded round runout concentricity from .003" to .045" at 1000yds.

[@USAACbrat]

You are helping a lot of reloaders.

[@FClassJohn]

Thank you.

[@AbgehaX]

especially over here in EU. cant thank you enough cause we dont have this kind of gun culture. Much appriciated

[@Lethalmuffin87]

Wow. I just picked up a runout gauge and started stressing when I had a few bullets over .002 runout that wouldn’t seat in a headspace gauge. This helps reduce that stress immensely knowing that the wobble will correct itself in the chamber sufficiently enough that I don’t need to redo all these bullets or adjust them down to .001 You’re doing a great service by showing us what we can do to streamline and I cannot thank you enough sir 🎩👌🏼

[@Chevy2U]

I started down that rabbit hole, but quickly realized there are other steps in reloading that gave better gains. Thanks for confirming 👍👍

[@sawhill729]

Hello Mr. John. I hope I took the right information from your video. We shoot local club matches at 100 and 150 yds. We shoot for all cash, anywhere from $100 to $200 dollars a shoot. To win, you need a perfect 50 at a hundred yards, and 48, 49, 50 at 150 yards What I took from the video is, concentricity's not going to get me into the high 90s. You and Eric have the most informative videos out here. Thanks.

[@erich9111]

The chamber straightens a lot of that out. Your comment about the seating depth moving when you chamber these seems like the best explanation to me. A better test would be average budget reloader type runnout vs full OCD F-class reloader type runnout.

[@FClassJohn]

Thank you and your comment is probably a fair one. Lots of other things to consider like I said and I'll work on doing more testing on this soon.

[@napsguns]

@@FClassJohn you could try chambering a round and getting it out, then measuring the remaining runout to verify

[@newcreation2521]

Oh good, you've relaxed my OCD paranoia. Thanks!

[@mikemcallister9091]

Greatly appreciate all the amazing videos. Learning a lot from these. Just tried the ThorroClean from your review and was very pleased with how a 22LR barrel came out. IT was very filthy, oh and I did get a good bore scope. Per your recommendation. Thanks for all that you do for us wannabe long rangers..

[@FClassJohn]

I appreciate the kind words and I'm glad that you're getting good results with ideas form the videos.

[@kevingeary1472]

I've heard people saying it doesn't matter but thank you for the test to verify it!

[@TubeDobs]

Interesting to see SD and ES changes from the 3 groups. I sold my concentricity tool gauge loooong time ago.

[@ericrumpel3105]

good point on the ES/SD.....&....lol.....I quit using mine about a half-dozen years with in 3 months of buying it,.....so,.... Copy That

[@ElfstersRiflesandReloading]

Very interesting! Thanks!

[@FClassJohn]

Glad you liked it!

[@maddan.]

Possibly some of that vertical could be attributed to the increasing velocity spreads as well as the runout.

[@ff4937]

Thank you for conducting this test. Extremely valuable information.

[@FClassJohn]

Glad you found it helpful.

[@MMBRM]

You can't say it does or doesn't matter unless you try it in multiple chambers and with multiple jump/jam configurations. Obviously a newer style match chamber with very tight free bore will be more forgiving(the bullet is physically prevented from being far out of concentricity) and if you are jamming the bullet in the lands the lead in/lands themselves will correct most concentricity issues. However, in a situation where you're jumping the bullet it definitely makes more of a difference. I've done extensive testing in benchrest guns and it definitely matters when you're trying to squeeze out every little bit of accuracy.

[@misterlewgee8874]

I was wondering about how much jump too...etx

[@ls2005019227]

Excellent test, with nearly unbelievable results! Thanks for sharing & would love to see more testing-

[@redrock425]

The biggest issue with all of this is separating the noise. Assuming a perfectly built rifle, shooter ability and wind are the two biggest factors. The minutiae of reloading have a much smaller effect but are easier to measure and control. I suspect putting a lot more effort into shooter training and wind calls will give much larger gains.

[@rustynut1967]

That was great! Thanks!

[@thompsonjerry3412]

Had to severely affect neck tension.

[@kajhelin6822]

Great test! Could you bend a few more cartridges? Chamber them. Remove them and measure run out again. If your bullet is .284" and freebore diameter is .285" the cartridges should measure only 0,0005" of runout at the bearing surface. Brass springback not accounted for. The bearing surface might be 3/8" infront of the case mouth in your cartridge.

[@FClassJohn]

Several have asked for me to do things like this and I will definitely follow up with more of this.

[@kajhelin6822]

@@FClassJohn Thank you.

[@unclenick222]

One thing worth realizing is that the degree of the tilt effect on point of impact depends on the bullet shape, rotation rate, and its time of flight (TOF) to the target. The amount of off-axis bullet tip that gave A.A. Abatiello about 0.5 moa of group size increase with the old M1 Type 173-grain National Match bullet in 30-06 back in the 1960s (The American Rifleman article on this test was reprinted in the NRA book Handloading in 1981) fired at about 190,000 rpm gave Harold Vaughn about 0.2 moa of group size increase in his book Rifle Accuracy Facts (25 years ago) shooting a stubbier 68-grain 6 mm BR bullet at about 167,000 RPM (high side of runout marked on each cartridge and then rounds place in the chamber with the marks at 90° intervals around the clock to get worst-case impact). Vaughn's results would have been more like 0.27 moa if the RPM and TOF matched. In addition to spin rate and TOF, the lateral drift imparted is determined by how far the bullet's center of mass (CM) is from the geometric center of bullet tilt in the bore and the actual tilt angle remaining after entering the bore. The bigger the separation of CM and tilt axis, the further off the bore axis the CM is for each degree of in-bore tilt, the greater its rotational speed, and thus, the faster it is thrown tangentially away from the bore line at the moment the rifling lets go of it. That drift is on the order of a few inches per second, typically, and is too slow for drag to reduce it significantly before the bullet gets to the target.

[@DadWil]

Thank You for doing this test & demo... I have not gotten to the point of even measuring the runout on my loads... Like EC told us in one of his posts so much of this stuff does not matter.. well at least to nimrods like myself they don't matter... BTW I like the beard contrary to what EC tells you.

[@DLN-ix6vf]

I always thought the barrel would sort things out as the bullet travels down the bore twisting in the grooves ! Personally I think a major runout just tells you your equipment is wearing out that's all.

[@FClassJohn]

Bingo....👍🏻

[@SigmaBallistics]

it depends on the rifle, a factory gun with a sloppy freebore may benefit from better concentricity where there is good possibility where the bullet can enter the rifling crooked in a match/custom chamber the specs are much tighter and things will align much better upon chambering and straightening things out in the freebore

[@AutoTrickler]

Really interesting. Small samples, but the results beg for more testing. The small group was super small, and the large group also had a large ES and the group was vertical so it seems likely the vertical came from velocity spread. Whether the runout affected velocity spread… I would think not but maybe. I suggest if you feel like it do 20 rounds perfect vs. 20 rounds which are visibly crooked and if the results are different enough, we can run some stats on it.

[@FClassJohn]

Sounds good. I’m definitely going to do more.

[@MMBRM]

My guess is that when the freebore/lead in straightened the bullet out when the bolt was closed it changed the neck tension as the neck would now not be contacting the bullet the same way after being stretched out. That could easily be where the increased ES/SD came from. Even by hand if you wiggle a bullet back and forth you can easily then pull it out of the brass with your fingers.

[@murder0ne]

The increased ES/SD and thus vertical dispersion is due to increased drag from off axis bullet wobble. The more run out you have the more the axis of the projectile will wobble from the trajectory axis and thus induce more or less drag round to round.

[@br4713]

Some benchrest shooters measure the projectile runout with a micron comparator. It allows to detects issues when swagging the bullets (voids between the jacket and the lead core). Bad bullets often go out of the group

[@gc5Hayward]

Awesome and informative. Thanks

[@nt_wicked_bunch2717]

Thanks for the video John, I always enjoy your videos especially anything reloading. This is a little off subject, but I’m was getting massive amounts of run out on a 17 fireball. I run expander mandrel on everything I reload, come to find out all my small bore mandrels were slightly bent. Which isn’t hard to do on them little guys. Just something to look out for. I’ve never noticed it on the bigger bore expanders but I’m sure for those use the decap rod in their die I’m sure it’s possible in that situation as well.

[@br4713]

Hello, instead of using expanders you should try to only use bushings on annealed brass to get the right neck tension (about 0.002'). The more you resize your brass, the more runout you'll get. Annealing your brass will give you consistent neck tension. If your brass hasn't been annealed for a long time you can get unconsistent neck tension with the same inside neck diameter. Great little cartridge 👍

[@garysreloadingroom]

Interesting test John. You mentioned that you thought that the bullets on the rounds that were really out, could have been pushed back further into the case. Food for thought, the bullet could have been pushed more into alignment by the chamber as the bolt was closed. Regardless, it was a very interesting test. Thanks!

[@thadrobinson8343]

I agree, and my 2-cent speculation is that the long, parallel central section of the bullet shown would tend to be aligned by the leade; a cartridge loaded for serious target shooting would be likely to touch the lands which would exert a further aligning effect, assuming they are themselves concentric. Perhaps a relatively short-for-caliber bullet could experience less "realignment by chambering" and exhibit more downrange dispersion?

[@garysreloadingroom]

@@thadrobinson8343 I'd also suspect that John runs a tight chamber, and coupled with the long-for-caliber bullets would further tend to realign the bullet to the chamber axis. Just a guess on my part, but I will still stick with loading on my Forster Co-ax which produces .001 or less run-out. It may not make a difference, but it is just another variable that is controllable.

[@sgt84bravo40]

Thanks for confirming my suspicions by actually shooting at 1000 yards. Shooting from a fixture in the Capstone 300-meter test tunnel can provide an indication of how runout might affect grouping, but actual shooting of those horrendously non-concentric rounds at 1000 yards shows that ultimate ammo concentricity is not worth chasing. As you implied, other factors will affect precision to a greater extent. Plus the quality of your rifle's chambering job is evident in how the worst rounds "straighten out" as you force the bolt home. Another great video - keep 'em coming!

[@joearledge1]

A lot of people have demonstrated that concentrisity doesn't matter(Johnnys Reloading Bench, Winning in the Wind, Bolt Action Reloading, and others I'm sure) they've done it with factory ammo and hand loads. Usually something like "the worst 5 cartridges with 0.003" to 0.005" vs the best 5 with less than 0.001" runout". Often there is no difference in the groups and sometimes the worst 5 cartridges shoot tighter and/or have better stats than the best 5. The problem with their videos is that most are hard to find because they don't have "runout" or "concentrisity" in the title. Most of the videos were being made for a different reason(testing a product or new bullet or just generic reloading) and they just happened to decide to do a concentrisity test. The videos are great, just not easy to find because concentrisity wasn't the primary subject of the video. Never have I ever seen someone shoot 0.020" to 0.040" visibly crooked rounds for groups, especially a precision long range competition shooter. I'm excited that people can easily find your video and that the concentrisity is worse than what a lot of plinkers are willing to chamber and it's at a longer range than 95% of people ever shoot. Translated to 100 yards the groups were 0.4" to 0.8" with rounds so crooked they would barely chamber. This is about the best evidence so far(also supported by the results of others) that if it's not visibly bent off to the side, it's fine, even for long range precision. The only caveat is if you shoot competition where 0.001" in group size difference matters, even then I'd question whether that difference was just by random chance or one of a dozen other factors. Great video Sir! Keep up the good work!

[@FClassJohn]

Thank you for the kind words.

[@elwhastrummer]

Good to know. And even better, it didn't take 40 minutes to explain. Thank You

[@FClassJohn]

Glad you liked it and I try not to take any longer than the subject requires to explain. Why drag it out is my motto.

[@darrellh1840]

Interesting video…thanks for sharing!

[@scarter176]

Great example John

[@FClassJohn]

Thank you and glad you liked it.

[@whiskeytango9769]

Once again, it comes down to the guy behind the trigger.

[@joeschuster2837]

thanks for the info. well done

[@barrygrant2907]

I just roll the round, and if the tip doesn't wobble, I call it good.

[@F15ElectricEagle]

Bingo! Same here.

[@jonathanrogers9961]

If you are hard core into precision shooting, yes, it will matter. However for then general reloader, no.

[@luv2fly386]

It would be interesting to determine how your action corrected the extreme runout when your bolt was closed. The extreme runout may have been changed to meet the dimensions of your chamber due to the extra effort required when your bolt was closed. This is another great piece of data to consider in the quest for accuracy.

[@bkmastr]

If the chamber didn't at least partially "correct" the runout on the worst of the worst, then there's something wrong with the chamber!!!

[@misterlewgee8874]

If chamber did correct bullet...to a degree...then ..neck tension is surely different..probably looser ..

[@ctech01]

Great info Sir, Thank You.

[@jimcheatham8306]

You answered the question why it doesn't matter when you said you had to force the bolt closed. The chamber and barrel is realigning the bullet.

[@CJ-ty8sv]

Given the typical chamber clearances in the free bore the high run-out cartridges are going to get straightened out pretty substantially upon chambering of the round. For example, if you have say 10thou TIR at the leading edge of the bearing surface (full bullet diameter) right behind the ogive and you are running say 2 thou of free bore clearance (1 thou radial), well the bullet has no choice but to straighten out to about 2 thou TIR (maybe a thou or two more depending on how much the bullet itself deforms or gets scraped while chambering which should be very minimal if any but will also show any shifting of the case within the chamber which again will be very minimal so the two aspects compounded will only add a thou or two ). This is one of the reasons why for the longest time before reloading equipment and components themselves got really good, match / tight chambers were always more accurate than loose / hunting type chambers, the chamber naturally helped fix errors from the loading process during chambering of the round. Essentially you are forcing the cartridge to conform to the specs of the chamber if it wasn't already a really close match. If you wanted to test this, you could make up a couple rounds that are way out of round, chamber and extract them and recheck both the concentricity and the bullet seating depth and see what kind of changes you get from just chambering the rounds. I can pretty much guarantee you that you will find the concentricity is much better and that the bullet might be ever so slightly seated deeper. Now this is not to say that you shouldn't worry about concentricity because even though the act of chambering straightens it out because it does so while leaving pressure contact between the bullet and the free bore and possibly the ogive and the leade and can disrupt the way the bullet engraves into the rifling upon ignition which therefore can cause the bullet to be cocked in the bore and this will shift the POI and the overall accuracy.

[@richardphelan8414]

Looking forward to improving my hand loads been shooting for a lot of years but now going after 1000 yard range now with a 6.5 Creedmoor re

[@burrco3086]

Prepping brass matters. A lot more than what most think. But like an old man told me a long time ago... You can go to far.. and waste time.. what ever works for you. But I will listen to what people say

[@theLTrain700E]

So glad I never bought a concentricity gauge. Money that went into buying Quality components

[@reloadingfun]

I bet that change in group size is from a change in seating depth rather than a crooked bullet.

[@dalehorkey4476]

How tight is your chamber? What I mean is if you would have closed the bolt on all of the round then taken the round back out of the chamber and measured the run out again would you have been able to differentiate what group they were in prior to chambering? Or how much run out will your chamber allow before closing the chamber "fixes" the condition? Is that even possible or is my line of thinking flawed? Is the precision of a custom chamber such that run out is less important as compared to a factory rifle which could allow more run out to remain, making run out possibly play a greater factor? Very curious to learn more from you on this

[@MMBRM]

Yes, different chambers will allow for different amounts of run out when the bolt is closed. The newer match chambers with long throats/tight freebore are specifically designed to mitigate run out issues. Also your seating depth matters a lot because if you're jamming the bullet the lead in/lands will straighten it out. The combination where good run out matters the most would be a looser/older spec factory chamber with a jumped bullet.

[@dalehorkey4476]

I would be curious to see that test in a side by side comparison.

[@billclifton8400]

I used to fret over runout until I heard you or Erik mention it didn't matter. After that I tested from almost zero runnout to, 010 and could not tell the difference on target.

[@daleguthormsen8555]

nicely done!

[@DimaProk]

Those are going to be hard to see on film.... you can see it from space lol how crooked they were! 😅😅😅

[@dirkvanvuuren2598]

How far were you off the lands? If you're in the lands the bullet would be "corrected" when chambering the round. If you're jumping say 80thou then I'd expect the effect to be greater. What do you think? Interesting test. Keep em coming thanks!

[@BelieveTheTarget]

I was around .021' off the land with this test. It's hard to say if it would be much different at .080" but definitely something I can play with next time I do more testing on this.

[@patrickcolahan7499]

Interesting outcome. I would have expected a much greater separation between the different test groups. What were the conditions like? If they were exceptionally calm, would the group separation been more dramatic. Don't know. Even at my shooting level, with all the steps I take to make every round exactly the same would I chance something like this. But is is interesting. Thanks for sharing.

[@FClassJohn]

Glad it helped and conditions were very mild.

[@jimbefit3073]

THANK YOU! & Well damn, those bullets are LOGS! LONG Bearing surface.. wee bit self centering?☆ 6 questions: How about the SAME TEST..... with Light bullets? If there was a big difference- THATS where I'd expect to see it. Ps: is your action controlled feed? How about chambering a round, then remove it and re check it for run out? How much did the throat straighten it out? Is it a tight throat? Is it one of those manufacturers that KEEP CHAMBER tolerances- ON THE SMALL (TIGHTER) END of SAMMI Spec???

[@dt3852]

Thanks 🙏 for testing this! Do you think it be better if use neck sizing?

[@misterlewgee8874]

That really was surprising...sub moa with huge runout...🤯

[@FClassJohn]

More tests coming with hopefully even more surprising results.

[@SixOFord]

Totally unrelated question here. Where do you get the orange ammo boxes you're using ?

[@juliusjames5577]

Concentricity guage is for sale now Cheap! Any takers?

[@ImNoBSING]

What about a gun that has larger freebore and therefore the bullet just remains crooked?

[@sadmazOR]

John hi. Appreciate for your tests. Colud you pelase test 0.0005 and smaller runaut vs your(and mine too) working 0.002-0.003 runout.. I wanna order custom non-bushing FL die for my FTR(2013 US Team reamer chamber) but doubt will it better when my redding bushing type-s..

[@Honkers716]

Bullet depth matters most. That's how you tune a certain grain powder weight. Run out doesn't matter

[@scottnj2503]

Sir, much respect for your knowledge, expereince and skill. I am new to long range shooting and accurate reloading. You mention having to "forceably close the bolt" on the high runout rounds. I'm curious about your thoughts...How much correction to runout do you think that makes? My hunch is its fairly significant, leaving the major remaining factors, the nut behind the butt, uneven neck tension and an odd jump into the lands and groves.

[@anthonybending2687]

If brass is resized to minimum, 1th per side and throat is 4 tenths of a thou each side then it dosnt matter, it practically self alline , so depends on reamer specs and how much clearance you have,but you carnt have more run out than chamber specs allow

[@FClassJohn]

Yeah valid point. I'll do another video covering that scenario in the near future.

[@anthonybending2687]

@@FClassJohn but , the less run out the better , which you proved, I load in the lands and light tension, so they self align even easier, good vid this, 10 points for it

[@jamespollard1670]

Good stuff .

[@FClassJohn]

Glad you enjoyed it

[@reloadingfun]

It would be interesting to see what the length of crooked round is after it is pulled out if the chamber. I also wonder if neck tension is changing too.

[@CrashRacknShoot]

I'd bet some of those cockeyed ones were too much of a bear to get in that he didn't want to chance not getting it out until it was shot lol

[@samuel-JF1981]

What caliber is that? 7mmPRC? Looks a lot fatter than 308 in your hands... 😅

[@thelonggunner762]

I've tried telling people this and they never believe me. The throat is to tight to let the bullet be out of wack that far. The danger lies in the damage done to the bullet to get it loaded into the chamber and straightened back out.

[@wrstew1272]

You need either a 1” dial indicator, or a ruler to measure some of those! But the throat will help some…..

[@jessewerner4067]

This is not surprising at all. When you close the bolt on a round in a match throat that is typically .0004"-.0005" over bullet diameter, it has no choice but to come into near perfect alignment with the rifling. This is why I never even check my runout, the throat will align it no matter the runout. I expect if you did this test in a sloppy SAAMI throat, you'd get much different results

[@redrock425]

I agree my .308 Tikka seems to have a lot of space, my Berger 155.5gr are miles off the rifling.

[@jessewerner4067]

@@redrock425 you're talking about bullet jump or distance to the lands. I'm referring to the side clearance the bullet has in the throat or "freebore" area. Factory chambers can be excessively loose while custom chambers can minimize this clearance

[@patmurphy989]

I noticed the extreme spread was much higher on the "Bad" rounds compared to the "Good' rounds. Might this have more of an affect on the vetrtical than the run out??

[@reloadingfun]

Yes, I suspect seating depth and neck tension were affected in this test. Which I'm guessing is the cause of that.

[@jturner5227]

I was expecting bigger for the last group. 8 inches plus. Do I really need to worry about concentricity?

[@johnplummer1619]

So if you have a good chamber " TIGHT " and your bullet is in the land will this reduce the run out ?

[@danielfinke6677]

What ammo boxes do you use?

[@FClassJohn]

I used these amzn.to/3Tyw8NP

[@jeffsikula2920]

Hey John...Let me ask you a couple of stupid questions...Do you think benchrest shooters are ok with .035" runout? Can a benchrest shooter maintain .100" -.200" group at 100 yards with that much runout? I only ask because I think many of us here want as 'perfect' as possible...one less thing to worry about. That being said.. I dont check case runout anymore I only check once every hundred rounds for bullet runout.

[@FClassJohn]

I honestly can't speak to what Benchrest people find acceptable. I don't disagree with perfect as possible but in F Class I think many people have the same thought as you simply because there's point where you find that it probably rally doesn't make enough difference to warrant additional work but of course every person will find their own journey with stuff like that.

[@jeffsikula2920]

@@FClassJohn Thanks John, I appreciate the response. For shooting and reloading.. you and Erik are the only ones I watch. ; )

[@5stargunsandgear]

What are you using to detect your shots on target

[@fentonpainter7907]

Shot marker

[@5stargunsandgear]

@@fentonpainter7907 thank you

[@michaelhill6451]

The more I learn about reloading, the more I am realizing that most of the stuff reloaders obsess over make almost no difference in how the bullets group. I am really starting to think that the only things that truly matter are your type of brass, type of bullet, type of powder, and type of primer. Everything else (even powder charge) likely doesn't impact precision in a statistically significant way. I think many of the procedures around reloading are based on the past when, for instance, barrels were thinner profile and powder, brass, primer, and bullets weren't manufactured to the same standards they are today.

[@CplSkiUSMC]

I don't think you would get the same results with just a run of the mill factory barrel, say a Remington 700 or a Savage. Chamber tolerances, throat, and the overall barrel quality make a big difference in accuracy and if you're struggling to make a factory barrel shoot well, you've gotta stack the deck in your favor by taking out as many other variables as you possibly can.

[@Jacoby4465]

What is the name of that guage?

[@FClassJohn]

It's this one bullettipping.com/products/concentricity-gauge/

[@DisgustedGenXr]

.040”??? More like .125”. Or is that measurement from the igive?

[@FClassJohn]

Yeah it's honestly hard to say because they were so out of whack like I said in the video. It could've easily been more than .040"

[@stephenthompson9722]

I don't check any of this stuff so aim watching this hoping that it doesn't matter at all haha.

[@johnleake708]

thanks the shooter makes the biggest defference....

[@annahonorata990]

Concentricity fetishism washed over the reloading community in a huge wave couple of year ago. Most of us have runout up to 5thau. Those winning the match are winning not because they have 3thau less runout.

[@williamkillingsworth2619]

You don't need to measure it. Roll it on flat surface and you can see run out.

[@SigmaBallistics]

I personally found the best runout tune between 0.010 and 0.015”. 1/8 moa groups all day. totally kidding btw, very interesting and informative test. As always, thank you for the great content sir! just curious, did you feel increased resistance in the bolt when chambering the heavy runout rounds? i’d imagine they are getting straightened out a good bit by the freebore upon chambering?

[@garyjohns4711]

What I gather is {normal} runout doesn't matter much!!!....

[@asullivan50i]

Hah, no need to zoom in we can see it.

[@JinkxSoldga]

Are your skills and equipment good enough to matter? Odds are no lol.

[@lewisgarland4025]

why would you load them or even try to shoot the ones so far out of measurement? Maybe you should take more time to reload them correctly seat the bullet to the correct depth and the issue with you having trouble closing the bolt because you incorrectly loaded the round .

[@darrellblanchard2362]

If your dies are right checking concentricity is a waste of time.