Ep. 078 - Let's Talk Barrels with Jeff Siewert

On this episode, Seth is joined in the studio by Author and Engineer, Jeff Siewert. This show is all about barrels; specifically, barrel materials, method of rifling, heat treating, and much more. Much like bullets, barrels play a crucial role in accuracy and performance, thus making barrels one of the most important components of any rifle build. We hope you enjoy the show!

[@ajheath5123]

Jeff has forgotten more than most could possibly imagine. A National treasure.

[@danielymoore]

I have a lot of experience with composites, having designed and created carbon fiber suspension components, wings, sailboat parts, and more. The specific stiffness of carbon is much higher than any metal. The actual stiffness of the carbon in line with the fibers can vary depending on the type. Layup is critical to achieve stiffness. Harmonic stiffness relies on specific stiffness. (Look up natural frequencies of a cantilevered beams). A lot of wisdom in this podcast.

[@waynesasser881]

I haven't been this engrossed in a conversation in years. Thanks Guys!

[@georgecolee7663]

For those of you wondering Schneider barrels makes the Polygon rifling that Mr. Siewert mentioned. Let me tell you they work! I love the nod to the old school 30-06 still just plain works. Now onto which barrel contours are most effective? How heavy a contour do we really need? To flute or not to flute? Which is more accurate Stainless or Chromoly? Twist rate is over stabilizing as big a factor with today’s bullets? How much more heat/friction is created with the faster twist barrels? I’d like a round two please!

[@daveknowles3055]

This is a podcast that is screaming for indexing. With indexing I would be able to revisit certain parts as I require more than one listen to have the information penetrate on some topics.

[@active4delta]

This

[@KS_Penetrator]

Double this

[@chipsterb4946]

And I triple it! 10:30 barrel manufacturing process 15:45 cutting rifling 26:23 carbon fiber wrap 28:24 rifling considerations and geometry

[@anthonykaiser974]

I was really geeking out as a Field Artillery officer (recently retired cannon guy), when he was talking about how the muzzle brake on a thinner barrelled 155 was affecting the projectile coming out of the barrel.

[@donnelson8121]

Wow his math sucks

[@n6mz]

I could listen to Mr Siewert for hour after hour after hour. What a treasure.

[@freeandfighting3069]

As a shooter & a retired tool & die designer & maker, I thoroughly enjoyed this podcast. FREE

[@darrenjones2933]

This is the most amazing technical firearm video I've ever seen. Kudos to Hornady Manufacturing videos and also to Mr Siewert. Well done!

[@aaron.from.winchester6744]

This is the most fascinating podcast you all have done. I listened to it twice.

[@chunglow7646]

Dang! Beats staying Uninformed citizen! Safe travels past 2023 in Harmony

[@unclebob540i3]

Agreed, this was exceptional.

[@yukon4545]

Another eye opening interview is Erik Cortina with Mr. Krieger.

[@Bhartrampf]

When I worked for Bo Clerk in the 90's, we button rifled with just flooding the bore with lubricant and then double heat treated them. We pulled the button through. I learned a lot from him, it's amazing how much technology has enhanced not only how rifling is done, but how to see if the barrel is straight and testing it. Pretty awesome stuff.

[@BowWowPewPewCQ]

Wow! Perhaps the most enjoyable, educational podcast ever. I've got decades of experience in high-tech / unique manufacturing design, so I could hang with him on the concepts and applications. What I would give to spend an evening with him. It's great to listen to someone so knowledgeable. Thanks for providing it.

[@hornady]

Great to hear!

[@GunsWin]

The fracture toughness test Jeff refers to is called "Charpy" in the metals supplier industry. The test required 2 specs, ft-lb of hit and a temperature, usually below 32F, sometimes as low as -100F, because metals are more brittle at low temp. A standard 3 sample test runs about $450.00 around here.

[@arthurshingler2025]

Yeah.... I could watch this ALL day.... over and over again. Unfortunately I only have 24 hours in my days...!! Great interview!

[@johnfrost8260]

Wow! It's great to find such a knowledgeable person discussing a critical aspect of shooting. Amazing!

[@FergusScotchman]

I had complete flashbacks of my college civil and mechanical engineering classes, and the machine shop we had. His job sounds so fun and enjoyable.

[@jeffsiewert1258]

It was a wonderful career.

[@FergusScotchman]

@@jeffsiewert1258 That's amazing. I've been 30 years in medical devices, but I do a lot of inventing and clinical trials. I have a request, and this would be amazing to hear you speak about. Do you remember in the late 80s, I believe, a manufacturer (Remington?) introduced an electric spark ignition rather than a primer? It was a bomb, but you wonder if these things have their appropriate times.

[@jeffsiewert1258]

The 20x102mm ammo used in M61 Gatling gun is electrically primed, during development it was thought that electronic primers were the way to ensure reliable ignition at high firing rates. These primers are susceptible to ignition from radar waves, so the trend has been to mechanical primers of recent. I can’t think of a good application at the moment.

[@gregorymccullough3801]

This is the most informative program I have seen on this subject in the 67 years I have been shooting.

[@wesleyjamison4442]

Excellent podcast. Jeff is such a wealth of knowledge.

[@john-venters-outdoor-services]

Interesting points throughout. Very informative. On the suppressor fixture point. In Europe we have various options of double contact mounting solutions. Screw the mod on and have a tight fit bushing 3 or 6" back. I've noticed Americans in particular love bayonet/front mounted moderators. I had a mod that had such a tight bushing (Teflon I think) that it rubbed the front threads onto the barrel finish. That was the most consistent rifle I ever had. No mater the powder, bullet or factory load it was a genuine 3/4moa rifle all day everyday.

[@unclebob540i3]

What a great geek out session. Please do this kind of cast more often. This is by far one of the most informative podcasts You have ever done.

[@rpink06]

Best 1-1/2hrs I’ve spent on KZbin…just an amazing wealth of information. Thank you!

[@jeffsiewert1258]

Thanks!

[@JeffHenry-uo1nz]

This was another great video. Last year after the first ballistics video I was having trouble keeping up. So I contacted Mr. Quinlan for a list of books to read to be able to keep up with the ballistic conversation. Ammunition Demystified by Jeff Siewert was on the list. It is a great book to read to expand understanding of ballistics and I have no trouble following the discourse of these ballistic videos. V/R Jeff

[@jeffsiewert1258]

Exactly what i was going for! Enjoy!

[@josesuro3981]

@@jeffsiewert1258 Thanks so much for writing this book. I read it in small chunks so it would sink in. This is a classic book for the ages. Thanks again!

[@richardcurrin7812]

Interesting how complex things are that on the surface appear simple

[@formulajoe2]

Pure gold. Jeff is awesome.

[@quarterminutemagnums]

More to barrels than most can comprehend.......

[@user-re3qq7pi7i]

I bought his book! Great reference. It is helpful if you have some math and physics background. Don't let that stop you though.

[@markburke2533]

I have listened to old people who reloaded, bench rest competitors, target shooters and back yard shooters, in a group and separately, that have knowledge like this. It is both interesting and mind bogling at the same time. That some guns shoot so well in my understanding is an accumulate of wisdom in making, and a gift from God to those of us who are interested at hitting the mark. Thank you for this conversation!

[@chasebricker639]

This was so awesome!!!!

[@stephenjohnson6841]

What a great podcast! Huge thanks to both of you!

[@chrisvonahnen3578]

Very impressive presentation 👍

[@Namegoeshere-op9hg]

This was awesome. Strong work!

[@tonybarnes5309]

Man, what a information overload I will have to relisten to this video. Over and over. Jeff has more insight into what a barrel is doing than any other person I have ever heard talk about barrel dynamics. Great Video Hornady

[@unajarre1629]

Jeff has a truly massive wealth of knowledge. I could listen to him again; I will definitely check out his website.

[@rmbettac]

Another great discussion. Feels like I learned a lot.

[@hornady]

Glad you enjoyed it!

[@jasonweishaupt1828]

I love watching old timers school young timers!

[@HephaestusSystems]

Incredible interview!

[@robstirling3173]

Some superb materials insights!

[@pjbarney9580]

some neat ideas. I like the less rattle and in gonna go back and redo them without the inside of the paracord. Thanks Bud! be safe and blessed

[@6mileoutdoors]

That was great Jeff, thank you.

[@jeffsiewert1258]

Thankx much!

[@thomaswall4285]

So much makes more sense now. Thank you for this, T

[@MrCptnawsm]

This was the most informative and interesting podcast on this subject i have seen to date. Thank you very much for an interesting session and spreading tons of knowledge!

[@hornady]

Thanks for listening

[@pagarb]

This is a great video. I shared it with the president of the SF Assn chapter 18, of which I'm a member. I was a medic cross-trained in weapons and demo, it occurred to me to pass along the link to someone who has more contacts in Special Forces because it's obvious that this guy's a really great resource who could do the cause a lot of good. Who knows, what he shares could save some lives..

[@jamesmooney5348]

Very good. Enjoyed it!

[@hornady]

Thank you very much!

[@jonathanmitchell3733]

ooooooooo Barrels, this looks interresting

[@BRADASSOFFGRIDHOMESTEAD]

Great one guys!

[@shoothuntride9456]

Once again, excellent and very interesting subject and discussion for a podcast. And bringing in top notch expertise! Keep up the great work! When people say “tolerances are better these days” when referring to marching, this podcast explains how much more.

[@hornady]

Thanks for listening

[@markyoung2981]

Excellent podcast, thank you for sharing this information with us, and for all the time and effort you put into this channel.

[@hornady]

Glad you enjoy it!

[@TTT-du6oj]

Buckle up Boys this should be interesting 👍

[@johnl5974]

Always great info. This series, all the info ammo makers use, is one reason I buy more ammo, and handload less.

[@michaelweber6034]

Wow! What an incredible program. I’m definitely getting the reference book. Thanks.

[@kansasscout4322]

Very informative. Thanks. Very much.

[@geraldbrunckhorst8291]

Thanks guys!!

[@hornady]

Our pleasure!

[@lesterwallis6617]

thank you i found this very informative a lot of what was talked about i have said for years i am glad to hear i am on the right trak

[@hornady]

Glad it was helpful!

[@Wmbhill]

Great podcast. Thanks

[@hornady]

Glad you enjoyed it!

[@BlueDogTabby]

Very informative!

[@catmanx]

Thanks!

[@Red_Proton]

Bound your constraints! That’s right. I love it.

[@timblack6422]

Wow. Nice deep dive! Scratches that geek itch!

[@lundysden6781]

The model 12 Savage target action is awesome. the floating bolt head etc. trigger was so new 15 yrs ago. still today thet are great. My dad has the current 800 yd senior f-class record in the NRA.

[@robertwoods3701]

Well,,,,,,,,,, this is the first time I've seen your podcast. Awesome! Yeah,,,, I subscribed and hit the dingy thing. Very informative and useful info. Looking forward to all that will follow. Thank you.

[@hornady]

Welcome!

[@derekmcmurry]

I've been told by barrel makers anytime you start removing exterior material once the OD is a certain contour, the bore diameter increases. That's one reason why many gunbuilders use an adapter when installing a suppressor, for example. Take a #3 contour hunting barrel, OD at the muzzle too narrow to thread it w/o interfering with bore diameter. That's what I've been told anyway

[@raywhitehead730]

Great knowledge, just bought his book on Kindle.

[@jasonrad9332]

2nd time around, still great!

[@stevemiller6044]

very interesting and informative

[@hornady]

Glad you enjoyed it

[@johnnash5118]

This is the most informative firearms science video I’ve seen to date. Validation of the polygonal land concept as a science is a game changer. Instead of a flat surface compressing the bullet to fill the grooves; polygonal lands are a knife’s edge with far less friction that cuts through the surface to fill the angled grooves. I have a Ruger M-77 Tang Safety that I bought in ‘83 that I rebarreled from .308 to 260 Rem AI. I chose Pac-Nor out of Brookings, OR. for a chrome-moly polygonal with a 1-8 twist. I love it. Perhaps it’s not a sexy enough concern, but I didn’t see any reference to “barrel whip” increasing per length of barrel.

[@benfadely9583]

I'm waiting and waiting for this conversation to get around to the Marlin microgroove rifling. 😮 There's still time I'll be patient LOL. I just subscribe to this hornaday channel podcast channel and I'm very happy I've had nothing but impeccable performance out of Hornady

[@jeffsiewert1258]

Not a big fan of “micro groove” rifling; the smaller the land diameter the smaller the in-bore angle & smaller the group size.

[@user-vj2wt7jh7j]

I was curious any comments on older military style rifles. I have a beautiful Swedish M96 Mauser FSR competition target sights on it, but when I took it out and shot it the holes were all over the target. I took it home and looked in with a borescope and about 1.6 inches of the throat was shot out. I found a CG80 barrel which is really a high end Swedish Mauser heavy target barrel built for target globe sights. It had a lot of dirt in the bore but once cleaned up was beautiful. The problem I had was the rifle was originaly built in 1907 so I had to remove some of the barrel at the receiver to get it off, and that 100 plus YO steel was some of the toughest steel that I have ever machined. It actually chewed up a carbide bit although Chinese via Amazon. I understand the Swedes used very high grade Vanadium steel. Any comments about these older military rifles although many consider the 6.5 Swedish Mausers the cream of the crop so many were turned into target rifles.

[@DadWil]

This is gold... I have Jeff's book and have read through it... So great to hear it from him... Thanks to Jeff for sharing his knowledge... My question for Jeff is on the OBT theory put out by Chris Long... Is there a inside barrel diameter distortion cause by a shock wave when a round is fired?

[@jeffsiewert1258]

Many moons ago, i was involved with a test on a hi velocity 30mm test barrel; we were launching a 300gm bullet at 5000 FPS. We had strain gauges on the barrel OD looking at when the bullet passed a particular point & fitting that data to the measured chamber pressure to get a handle on the base pressure vs travel in-bore. Saw bore growth as the bullet passed the strain gauges (oriented to pick up hoop growth), but nothing else. FWIW.

[@DadWil]

@@jeffsiewert1258 Thank You so much..again ...

[@ericb.4358]

MY IDEAL RIFLE BARREL: 1.) cold hammer forged chrome moly steel thin "core barrel" 2.) axial "maypole ribbon wrap" pattern carbon fiber wrapped LONGITUDINALLY TENSIONED shell. *Seth is an excellent host with impressive knowledge that always helps with asking the right questions and responses to the guest.

[@jeffreywilson690]

Would love to set on the porch and listen to this guy,hell I guess I am

[@tacticalrabbit308]

Im looking to get a barrel for an AR-10 in 308 win and now this pops up good timing guys

[@ThomasRonnberg]

Man i've listened to this like three times this is so goddamn interesting thank you so much i love it! Totally fascinated!

[@LucasHeinze]

Very interested to see real world tests on barrel tuners. Harmonics/forced vibration, can it be mitigated and how. Let's get to the bottom of this cult! The BOSS system made sense with the understanding we had at the time and it might still make sense but for different reasons we are just now beginning to understand.

[@The340king]

Fatigue typically starts from a notch root. Is there a particular surface finish that is done to reduce the chance of having a fatigue crack start. It would be interesting to see the difference a tiny bit of radius might make with fatigue resistance compared to performance. The idea of differential forces due to the thickness of the barrel would support the idea that a thicker barrel more accurate. This is due to the off center distance being a smaller fraction of the overall diameter. The gas block discussion also would support a thicker barrel, so the gas block difference is also smaller. Interesting thought provoking discussion. The tubes on our Howitzers were examined on a regular basis to catch the cracks before they were critical.

[@heightaddict]

VERY informative. watched the whole 1:29 😀

[@scottfrey5611]

Holy smokes this guy blows my mind! I want to hear his recommendation for best deer rifle, best elk long range rifle , best Varmint rifle etc. I would believe him !!!

[@chipsterb4946]

Does anyone out there know if 8.6 Blackout has the same wide groove/narrow lands design as 300 Blackout? With a 1:3 twist rate that would be extremely important.

[@georgelza]

just got his book... my next read. :)

[@LucasHeinze]

I know from some forums that the gain twist rifling has been played with a lot. I'm seeing that we need to revisit previously abandoned concepts because we are evolving in ways they might be plausible now or in the near future. Polygonal rifling has my eyebrow tipped a bit. With a less distorted bullet leaving the barrel ................ We hunger for more intel!

[@redrock425]

Just bought Ammunition Demystified, looks like an interesting read. Barrels are a gunsmith only job over on this side of the pond. Expensive (£1,000+) job and a long wait.

[@TheFORUNNERGaming]

Can you not legally change a barrel out?

[@redrock425]

​@@TheFORUNNERGamingThe only way I know of is if you have a switch barrel rifle but the barrels will have to all be registered to you and be proofed. AFAIK you can't buy prefit barrels here so rebarrelling would need some skills and equipment.

[@aaawman2280]

My muzzle brake is a witt clamp on, guess that's as close as I can get to what he was saying about mounting at the muzzle and back a little from the muzzle, in my case an 1 1/2 back from muzzle. Cool

[@rangervapes571]

Would love to hear Jeffs thoughts on barrel Tuners ie the EC Tuner

[@donbenson5292]

That is a thing hung off the barrel...lol

[@user-yb8ys1qp5q]

Fascinating guy, Jeff made the discussion very interesting. I’m gonna have to listen to it again and again.

[@bille5399]

Visual aids would be awesome

[@marcussamson7640]

marlin used "Micro Grove" for years I wonder why they did and had success but its not used in other manufacturers

[@m6jd]

308 family starts with 243 not 260. Sometimes I can reload 6.5 into once fired 243 brass with out the need to trim.

[@m6jd]

I have to correct my statement the 308 family started with 308 I don’t know how it branched off. I know it goes as small as 6mm could go smaller. I learned it goes as big as 38 from this video.

[@scottsammons7747]

At some point, I hope to understand how Blackstar polishing failed to produce.

[@m6jd]

@@scottsammons7747 I don’t understand

[@SOLDTONORM]

The composite barrel will have less mass toward the outside dimension. The more mass toward the outside dimension (like a Bull barrel), the less the effect of bullet spin leverage. This can sometimes be observed in overall rifle twist in the hands of the shooter when fired. The same advantage could effect end to end vibration, either vertical or circular. The ideal might be a large diameter composite with a steel outer sleeve for not only stiffness, but to resist torque.

[@joshrosemore2983]

we broach cut poly rifling and to have this man to show us how its done would be awsome. its kinda trial and error rn

[@lookoutnw]

Got one on Archangel stock. Vortex Venom with tankers brake compensator. Shooting 175gr,180gr, 198gr for different critters. Have original stock bayonet all issued items. Shoot it and my 3006 interchangeable for hunting and targets

[@Tofazfou]

Enjoyed the Vid and learned a lot of things. But, what I couldn't wait to do is, read the comments to see "WHO WAS SMARTER than JEFF" and I found it! Amazing how every video on KZbin who has an expert talking has someone in the comments that can find everything WRONG with the person interviewing. But why does that "smartass" not have any videos up on his channel explaining things better. KZbin comments "rant" over. Great video Hornady

[@chipsawdust5816]

Looking at SAAMI standards for several calibers I couldn't find forcing cone angle. Apparently it's not part of the standard or am I missing something? This was a great dive into barrels - there's so much more that unless we live like Jeff has lived, we'll never know 1/100 of it. This just scratched the surface. But thanks to people like him, we don't need to know much :)

[@jeffsiewert1258]

Just “down bore” from the case neck cavity on the chamber drawings is a (typically) small angle call-out (1.0-1.5 deg for new cartridges), that is the forcing cone half angle.

[@gordons.dempseyii1345]

Question on chambers. Why is the .223 the same now as it was for the 1/12 twist? Seems that it should be longer for heavier bullets.

[@jonathanmitchell3733]

Cold Hammer Forged for the WIN!!! If I do understand correctly, a Cold hammer forged barrel will last longer than other manufacturing methods (all else being the same)

[@jeffsiewert1258]

True, but the bore diameter variation may cause dispersion headaches. If you can lap the barrel prior to installing, I suspect you will be happier.

[@jonathanmitchell3733]

@@jeffsiewert1258 I don’t know the entire manufacturing prosess of Tikka rifles, but their cold hammer forged barrels are accurate as can be. The Mauser ones are “golden” as well

[@ThomasRonnberg]

Now it makes sense why 22s are so accurate.

[@john-venters-outdoor-services]

Watching again and talking about bore and barrel straightness. Would a hammer forgeded barrel have a more consistent bore line? My thinking is because the barrel starts out short and fat and is kneeded out like dough?

[@richarduk679]

Dear Hornady We are told that when we put a moderator or muzzle break on a barrel that it only results in a shift in the point of impact and not in a change in group sizes. Yet we know that tuners can be used to change/tune groups sizes. My question is. How does the barrel know what you’re putting on it?

[@ericb.4358]

Q: Can you address the advantages of 5R rifling?

[@williamsweet7511]

love the show...does shooting a hot barrel cause it to foul faster? Hot barrel causes the copper to get hot and melt, becoming more "sticky" also increasing pressure? Would different twist rate or types of twist also affect this?

[@jeffsiewert1258]

Hot barrels expand a bit (they have to be pretty hot) making the interior dimension grow a bit, pushing the contact stresses up, which increases the temp rise on the jacket, resulting in more jacket wear/melting. In-bore travel time is too short for much heat transfer via conduction to the jacket, so no, the jacket doesn’t become “sticky”. Faster twist pushes up the torque appled to the bullet, increasing wear & expected copper deposits.

[@williamradleyjr2577]

Heat causes metal to expand. Therefore the diameter of the bore shrink. How much smaller is the bore, I don't know.

[@ngallakp62]

Up the over barrel suppressor

[@robertsherrick6276]

Ok what is the best barrel to shot out to a 1000 yards