Ep. 071 - Let's Talk Cartridge Cases with Jeff Siewert
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- Опубліковано 10 тра 2023
- On this episode, Seth is once again joined by author and engineer, Jeff Siewert. This podcast takes a deep dive into cartridge cases. The guys discuss Jeff's experience with cases, their material properties, and how they interact with the chamber during the firing event. We hope you enjoy this educational episode!
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I watched this episode twice. I think it is one of the best reloading discussions I’ve heard.
Been reloading reloading since 1964 .this was a great podcast thank you Seth and Hornady for finding these amazing people and letting and or getting them to share their knowledge with us. Keep it coming please.
Like these detailed ballistic podcasts. I read Ammunition Demystified last year, a great book, well written. Keep bringing Jeff Siewert back to talk about all things ballistic.
Verified my experience which validated areas that Jeff discussed which I had not ever thought about. Great guy and hope he returns to share his expertise.
This guy is a good dude. You could do a 3 4 part reloading, accuracy series with him.
Great job as always!!!! I read the book after the last time Mr. Siewert was on and really enjoyed it. Definately not a one and done read though. His war stories are awesome!
I've also noticed that not only does case taper influence thrustback on the boltface.... but also amount of case body length can influence the thrustback. The more case length, the more surface area that there is to help grip the chamber and reduced thrust back on the boldface.
So together, a minimum case taper, with longer case wall surface area.... along with a clean chamber....all three influence case/bolt thrustback, when all else is equal (pressure).
As Ackley put it.... better gripping of the case in the chamber... influences bolt thrustback.
I've had blown case heads (separations) with a combo of pressure too high, in a "springy" action.
British NO. 4 action is horrible with case head separations along with the Savage 99.... both rear locking actions with a surprising amount of "spring"!
I've had a few in Marlin Lever Actions using short straight walled 44 magnum cased ammo, along with their rear locking actions.
For me, all were controllable by keeping the chamber pressures "reasonable"!
Hornady cases are very good. I use them when I can. I never had one burst but when I was young in my late teens I had a DWM .30 Mauser case yield and explode out from the receded rim of the case. The reason it blew was because of a balloon head case and mercuric primer contamination via the primer evaporating through time into the wall of the cartridge case. I took the case to my biology class microscope and I saw the silver color of the mercury embedded in the edge of the failure in the case. It was amazing how much metallic mercury was seen mixed in the brass. I never had a modern case rupture or explode.
Podcasts you do are very well done and educational. I work in a gun store and the things covered on all the podcasts have come up in conversations. Extremely appreciative of the knowledge of experts
I could listen to Jeff all day!
Years ago I ordered a 35 lb box of once fired 5.56 Lake City cases and processed about 2000 of them to make 223 loads using Hornady 60 gr V-max, and the rest to make 300 blackout brass before it was easy to get. I swear the boxes were labeled V-Vax, but that's another story. I sized each case, then trimmed them to length and then uniformed all of the primer pockets and deburred them on both ends, including the inside of the flash hole. Only after making the exterior dimensions the "same", I sorted them by weight. Right around 93 grains, I think... it's been a while. Loaded with 25 grains of Varget or the same amount of H4895, the accuracy was stupid crazy. I also crimped the cases very lightly using the Lee factory crimp die. Like phenomonal. Benchrest accurate all day long and yes, I've fired thousands of them. As a result, I've used the Lee crimp die on every rifle cartridge I've loaded ever since. Gotta get crimp dies, Hornady... just saying. Anyway, loading the same brass with no processing at all still gave excellent accuracy. Like still hitting eggs at 300 yards almost every time in good conditions. I only trim to length now if the case it too long.
Just found this podcast, and I am enjoying it immensely. Thank you for taking the time and effort to share this interesting information.
Glad you enjoy it!
ID chamfer is extremely important. I'm glad you mentioned it. Neck tension doesn't matter so much, which most people think that does more than anything else!
As far as accuracy goes sure but it does matter when it comes to magazine to chamber transference, particularly with short-fat cartridges.
I bought Jeff Siewert's book because of your show. I did not know it existed prior to listening to him speak on your show!
This was awesome! Please keep making these podcasts. I have learned so much from this episode alone. I am already redesigning my loading system to test what was discussed in this episode. I was very happy to hear that I could eliminate a couple popular myths from my system. I will be testing my new loads based on this information soon!
Thanks for the technical explanations. This is a great source of information for the geek wannabe like me. I bought the book. Love all of of this. I remember when to call a guy a geek was an insult. Now, I wish I were smart enough to be called a geek. Thanks, gil
Loved every second of it!!! Thanks Jeff and Hornady!
Glad you enjoyed it
Fatigue cycling. I love it! I did so many papers in college on this. To see it on real life makes me giddy. Bc of the advancements in cnc machines, we can reduce the case stretch by making chambers and brass a tighter fit. (Match grade brass and chambers like 6.5cm 7prc)
Those steps are noticeable, you get increased accuracy and increased gun life w/o a hand fitted and lapped gun. All from off the shelf parts
I appreciate the structure and elaboration of this subject. I have only recently become a precision enthusiast. The Complex Simplicity of Jeff's comments provide a guide of valuable information that Isn't too difficult understand. This content has got me asking questions that will require further research . Thanks Guys.
Another excellent podcast Seth.
Just make sure you keep onto your boss about how exceptionally important this kind of information is.
Without the customers knowing the truth, all companies suffer, particularly when so much information is disseminated so fast & easily, you & other companies will do much better to try to ensure that the truth is out there as much or more than all bullshit. The real truth derived from scientific proof can only serves to strengthen your position.
Another great video. Thanks for the time & effort Seth. Wonderful to see.
1:19:00 this was perhaps my MOST favorite anecdote in Mr Siewert's book. John Browning and Eugene Stoner rank near the top of my personal list of true geniuses.
I learned a lot just from this podcast! I'll certainly be picking up a copy of his book and I look forward to more content with Jeff! Great podcast!
I love these in-depth technical discussions and can't wait for the next installment!
Thank you, absolutely incredible!
You bet!
Podcast series is amazingly informative. So much to process. Despite reloading for too many years to admit, Mr. Siewert ‘s data & experience based information fire hose had me backing up the video for a 2nd, 3rd for a go. As you said: You don’t know what you don’t know. Picked up Mr. Siewert’s book & several of his articles … lots of homework. Great work guys.
Lots of nuggets out there on some stuper long reloading threads too. But mostly in books just like these. 👍🏻👍🏻
On the annealing side of things, I've got Lapua brand brass for both a 6.5 creedmoor and 338 Lapua. It work hardens so badly from firing that I've broken several expander/depriming studs. So, I've come to the conclusion that annealing is necessary with Lapua brass.
I had to get an AMP annealer to get my 6mm creedmoor Lapua brass to get the seating pressure I wanted. Annezee couldn't get them hot enough.
Thanks for sharing all of the knowledge on these podcasts, I listen to most of them at least 3 times. I am a 60 year old machinist and have always had a problem with people talking about .002 neck tension. Jeff is exactly right, .002 press fit is not neck tension.
Thank You for sharing. Learned a ton. Have lots to change in my reloading process. Hope to see more like this…
Very interesting conversation. I’d listen to more of this.
Another great video. More questions were answered without asking. Please keep these informational videos coming.
Great interview! I enjoy Mr. Siewert's interviews and he always has something to teach me that's new. I need to buy his books.
Very, very informative!
Absolutely love the work that you are doing.👍🤗
Best Greetings from Scandinavia
Thank you very much!
second Jeff Siewert podcast I've listened to this morning. Bought his book about 1/2 way through this one. So much good info based in scientific study instead of "that's what everybody does."
One of your best. Thanks!
In addition to making sure your cases are clean and dry, it is equally important to make sure your chamber is also. I keep a pistol length cleaning rod with a chamber swab on it. I’ll use acetone to lightly soak it and swab the chambers of my rifles prior to a shooting session.
Always interesting, and good information. Thanks.
Thank you. Very interesting and informative discussion. Will pick up a copy of Mr Siewert's book asap. Cheers.
When I get flattened primers I believe I'm near excessive pressure. You're talking about case seperation and primer seperation as common
I'm going to have to listen to this a couple of times just to absorb it all
Im so glad ive been absolutely loading with gloves and just wiping the hell out of my handloads this man is a genius
I really appreciated this guy's knowledge. i learned a lot.
Since you’re talking cartridge cases, can you make a sequel discussing why Hornady cases develop loose primer pockets faster than just about anyone else? Surprising since everything else Hornady makes is of top quality.
When I was younger and had a lot more .380 and 9 mm automatic pistols I did fire a .380 in a 9 mm P38 Walther and had no problems; just an expanded case.
Very informative. Thankyou.
Thank you for the deep dive on cases. I've alway used alcohol on a paper towels to carefilly degrease each case od after sizing. Glad I did after this podcast
Agreed about case wall stretching in the unsupported part of the brass. That's been my experience too.
Great podcast. I had never heard of this person, I’m going to order the book. Thanks
It would be interesting to get a general opinion on the difference, if any, on reloading military brass vs commercial brass!
I can't thank you guys enough for these podcasts! I'm a gunsmith in Montana and specializes in custom long range hunting rifles. I've started referring almost every customer to these podcasts because you do such a good job of explaining ballistics and how to discover the true accuracy potential of a given shooting system. It's saved me a ton of service hours explaining things to customers! I'm also licensed to reload...your debunking commonly held beliefs regarding load testing has changed my who reloading operating! Thanks for the help! I look forward to hearing the results of your upcoming research!
🤣 Ok, I Subscribed! Thank You for ALL the work that you do!!! 😁 It is Absolutely Wonderful!!! 👍🤑
Thank you!
🤠 Thank You!!! 👍😁
👨🎓 Great Guest! 👨🏫
best episode so far ;-)
So they sell Arbor presses where you can see the PSI used to seat the bullet. This is directly correlated to annealing and neck bushing size and/or expander mandrel. Neck thickness matters depending on methods used. Generally I know if it takes more than 40psi to seat my bullet, my brass wasn't annealed long enough.
Great episode, thank you so much. Just one question: Where can we out here get the QuickLoad++ you mention at your end ? Thx in advance :)
🥰 I Love your Guest here too! 😯
In the older video you posted, where Joyce goes through the process, he talks about neck sizing, and full length sizing, and he mentions that if you're firing the same brass in the same rifle, neck sizing is the way to go, because after firing the case has expanded to fit your rifle, and shouldn't need to be re-sized. Are we saying here that that was false? In his explanation, he said that the case OD expands until it touches the walls of the chamber, but there's nothing in the explanation where the length changes. The length changes if you resize the length, but if you fire it once, and it fits your chamber, it seems to me like neck sizing only would be the way to go, if it doesn't affect group sizes, and helps the brass last longer. Seth even said that's what is done at Hornady, just neck sizing, and since Hornady is concerned with accuracy, I would have to infer that there's no appreciable difference to re-sizing the full length. That being said, he had a case get stuck, which is why he then went to full length resizing, but he didn't mention if that one that got stuck was one he had never re-sized in the first place, but maybe hadn't fired from his rifle prior to reloading that round?
Love your show
11:00 Tubb and the elr guys tend to leave a little lube on their brass. Talking about case failure and having the brass stick to the chamber.. have you heard of case head separation? 14:18 you hear the guy say lube increases bolt load and somehow that translates to increased pressure.. two different things. 23:40 if you got a barrel that actually gripped a case you'd have it rma'd. 31:12 the belt on the win mag doesn't make it stretch. When you make your brass super short to guarantee clearance in the chamber, you have issues. When you take the belt away you have to make it right, or at least better, or it won't work. 37:30 no one reloads tank shells. The .303/.300 win mag issues encountered in reloading are a non issue. Reliability in the field was all that mattered and the .303 and .375h/h did their job. 40:04 I did a pistol seating depth test and it wasn't until I was .100" deeper that I saw any changes. Somehow, deep seating rifle bullets makes pressure go down but it makes pistol pressure go up. 41:20 I think I did that with a .50 cal. Long lead bullets and fast powder in a straightwall case, lots of bullet shearing at the end of the chamber. Had to redesign the reamer.
Good video. I am interested to hear a discussion about case design considerations. Specifically, (1) the compromise between case volume and overbore considerations and (2) what is the importance of shoulder angle?
Have a question for you. Why😂won’t Hornady support the 6.8 western? Of all the models in Winchester and Browning lines how many are supporting ALL the PRC calibers. Never heard them say we won’t support the Hornady cartridges.
Good podcast you taught an old dog some new tricks
Good show!
question, Re the co-effecient of case friction for brass and other metals, would it not also be how easily it expands and how hard it presses itself against the wall.
aka and this pressure impact with how much rearward pressure a brass case exerts via another material ?
Use cartridge cases with small rifle primers because I can buy them. I haven't seen large rifle primers on sale for over 3 years.
We are being played
Sometimes it's what YOU feel is the best, makes it the best ammo. Even if the scale shows variations in powder or case weight or the the chronograph shows large velocity variations..... if you are convinced that your ammos' the best.... with YOU shooting it, it shoots the best. The psychology makes it all shoot the best.
Unsupported case head expands under excess pressure... the Primer pocket expands too much, so that it is too large to hold a Primer in the pocket.
I had an accident with a 6mm where the case head expanded .01" ! The brass looked like a belted magnum case!
I had to pound that Remington 788 bolt open. The Primer fell out.
I hit the groundhog too!
I learned a valuable lesson that day.
A ball powder max load that was loaded and tested on a 75 degree day.... but shot the groundhog on a 95 degree day.
Temperature difference with that ball powder loaded too hot!
Keep loads below max!
Using small magnum primers in a case like 6.5 Creedmoor isn't necessarily a path to being able to run higher pressures, but at standard pressures, the pocket will last longer...
5.45x39 brass would be nice, and projectiles too! Show love to hand loaders.
I have a BS in physics and mathematics and suspected there was more to ballistics and firearms than I initially thought. Some thoughts on spin pressure of center I never knew. I'm starting to understand twist and stability. A very complex study. Wow
When I hunt I use factory ammunition. When bench shooting, I use for practice, I use handloded ammo to reduce cost and because it's fun. I use neck sizing. Since I do not shoot more than a maximum of 500 per year, I have the opportunity to test each ammunition that they do not get stuck into the barrel.
Yeah, I've had the experience with the casemouth jamming or "crimping" the bullet in the case when firing. Pressures really do rise!
I watch a light blue tint just below the shoulder which shows on some factory and military brass. It creates consistency bumping shoulders. Templiaq is needed
Im very aware of not sizing my brass shoulders too far back and far enough. I had some issues so now I find a case rhags tight and keep sizing it turning rhe die a tiny bit until the bolt just drops nicely. Then size all cases ro that size.
Very useful!
He has worked on some interesting tests for the gov't, and has seen some of the fun stuff they've done. Reminiscent of some of the stuff from Col Hatcher in his note book, and I'm betting some of that really hasn't changed much. A guy like Ken Oehler cpuld tell a few stories, he'd be another good one to have on, he's had exposure to some of the stranger aspects of ammo work as well.
I tried neck turning once. It WAS more accurate.
Neck sizing never gave my better accuracy. I agree neck sizing does only saves brass life.
What seems to contribute most is whatever will guarantee the most consistent bullet alignment to the bores' center.
I heard that brass was chosen because it allowed expansion and then returns enough that extraction is much easier. I am just wondering if thicker brass could expand less? Is polishing the chamber for what ever reason a no no?
Hopefully I didn't miss this but what about measuring case head expansion?
Is that a valid way to check pressure?
Learned some things and confirmed some things. Really the conformation is in the consistency. Top notch!
Can you help explain the failures being seen in 7PRC Hornady brass and Loaded ammunition? Also the issues with the 6ARC brass?
thank you much for the knowledge dump
1:03:00 multiple people have shown the same results in multiple cartridges, guns, shooters and ammo types(factory and hand loads) that run out doesn't matter in 99.999% of practical shooting. Possibly at the bleeding edge of long range bench rest international championships wins and losses or maybe ELR/ULR, but that data is still inconclusive on whether or not it matters in those applications.
I heard the 9mm case is not straight wall but tapered for a reason. Improved headspace. Improved centering of cartridge. ideas?
great info 👍👍👍👍👍
Glad you think so!
When yall going to put out some ELDX IN 300WSM haven't seen any in long time
Any plans for a 277 prc or 277 creedmoor cartridges
Yea we don’t polish chambers to a mirror finish for grip. Especially on autos. Especially especially if it’s guaranteed going to shoot steel cased.
Did Seth say you have to clean One Shot out of cases or was he referring to just wiping it off the outside?
You need an Amp annealing set up and the AMP press.
What happened to steel case line I loved the value
Carbide sizing dies +1. Damn you all, now I have to buy the book!
Sure wish your 6mm ARC cases were available.
YES!! Please make 6mm ARC cases available.
Yes please, 6 arc cases. I got one gas gun and one bolt that need to be fed. I like may others would really like to see these on the market.
I came to this video just to say something about 6 ARC brass lol
I wish they had 5.45x39 brass available.
Neck down 6.5 grendel you damn pansies
Question: will a long skinny case (30-06 / 7x64 / 6.5 x55 swede) be more effected by shortening the barrel than a short case (.308 / 300wsm / 6.5 creedmoor)?
I can't say I've ever seen a comparison of short, fat vs. long/skinny cases.. Wish I could help..
@@jeffsiewert1258 I got an answer in the meantime. And it is true.
Possible for you to share data??
.277 Fury/6.8x51? Can Hornady make their own version for other calibers?
Around 4:20 Seth describes "dumping primers" during a rainy shooting match. I assume he means the primers are being pushed out of the cases, but I don't see how water lubricating the cases would have that effect. Can someone explain, please?
So when he discusses the leaving lube on cases and the pressure on bolt face being double or more, that means too much pressure is going backwards. Wet cartridges are basically lubed. So extra back pressure which pushes out primers.
Wet chambers/ammo causing the case to swell and drop primers isn't so much about lubrication as it is that water is not compressible. If water [partially] fills the void between case and chamber, it causes pressure to spike which damages the case. Imagine sucking water into your car's engine instead of air/fuel gas. Pushing trapped water is hard on things. More air gap between the chamber and case will cause pressure to drop. Obviously too much air gap will cause ruptures.
@@georgejohnsmith No. If you make a cartridge/chamber fit exactly 1:1 with no radial air gap, regardless if that's done with incompressible case material or incompressible water, it spikes internal pressure. You need a couple thousandths of an inch clearance for things to work properly, especially in the neck. Increased bolt thrust from lubrication does not manifest itself in loose primer pockets (radial expansion). Excessive pressure from inside the case does. Thick necks that are a 1:1 fit into a tight chamber will show this immediately with what should be "standard" loads wrecking primer pockets and dropping primers.
Lightly lubricated cases, that only have a film of lubricant on them will cause higher bolt face load, but that doesn't manifest itself in radial expansion of the primer pocket. Lightly lubricated cases will in fact help brass life (less "grabbing" the chamber and stretching) at the expense of bolt load. Excessively lubricated cases (where oil/water/whatever fills the void between case and chamber) will spike pressure and wreck cases as well as provide extra bolt thrust.
Thanks for the better explanation of how you imagined water affecting primer push back. You are correct that liquid water is essentially incompressible and if that prevents the case mouth from opening and letting the bullet go early in the pressure rise (as is supposed to happen) then you can get higher peak pressures because the gunpowder has less volume to expand into (at least initially). I suspect the small intended gap between the neck and chamber would tend to wick water fully into that gap before firing if a drop was on the bullet or neck when inserted. The minimal loss of volume available for the powder to burn because the chamber is tight (either mechanically or because there is a liquid in the gap between the case and chamber) would only be a very minor contributor to chamber peak pressure (I think Siewert makes this same point elsewhere in this video). A higher peak pressure should, again all else being equal, increase the tendency to push the primer out.
Best explanation so far.
Does Jeff Siewert have any thoughts about "polymer" cases, such as those being used by True Velocity?
IMO, a steady diet of polymer cased ammo isn’t desirable unless your gun is specifically designed to use the plastic cased ammo. The peak bolt load is crowding double what you’ll see with brass cases.
Bolt face pressure..... is this a concern for bolt, semi, or both actions?
I watched this entire podcast after midnight and I could have listened to Jeff until the sun came up...fascinating listening
Question- About the one hour mark in the podcast your guest mentioned “ engraving “. What is he talking about?
Just reviewed the podcast near the one hour mark, couldn’t find what you’re referring to. Can you pin it down more precisely?
What a pity Hornady haven't done that sort of investigation and redesign on the 17HMR cases. The necks of these cases have been splitting for at least the last 5 years. I personally have has as many as one in ten splits in some batches.
Hey! If the cases are split along the longitudinal axis, the cause is most likely stress corrosion cracking. I’ve seen that on some older 17 HMR cases, haven’t seen it on newer lots. If the crack is in the shoulder, it won’t harm the firearm. Hope that helps.
Speaking of runout. When the brass is shot its concentricity is pretty good. But after sizing it introduces more runout. Not that I gauge it as to significant. But MY question is what causes this. Is it the dies? I have 3 presses and they all have the same result. So thats probably not it.
The increased runout after resizing probably comes from the clearance between the threads of the die and the press.