Case head separation and what it looks like before it happens

[@mln19631]

I’ve had brass that’s lasted the life of the barrel it was shot in, over 20 firings. The number of firings isn’t the problem. That brass has had the shoulder pushed back too far at least one time, if not multiple times. When the case is shortened via sizing it stretches back out upon firing. If the shoulder has been pushed back too far it stretches back out ahead of the web where it’s at its thinnest, right where those lines formed. That’s why most bolt gun people bump the shoulder back .001” to .002” only and gas guns .003”-.004”. Many pieces of good brass, quality brass, have been ruined by bumping the shoulder too far back. This batch you were given is proof of that.

[@robertsherrick4940]

It's head space not right

[@BurnDuration]

Mark Nelson agreed 100%. I was going to write exactly what you posted-but you beat me to it! Either FL sizing dies is not setup correctly, or headspace in the barrel is excessive.

[@br4713]

I agree with you Mark 👍 I'm also surprised that so many people dont understand why their brass cases get longer 🤔. Usually they think it comes from the caliber, shoulder angle etc... In fact they are just squeezing the brass too much when resizing 😀.

[@FClassJohn]

I absolutely agree. I did a horrible job explaining that aspect of what was happening but I appreciate you and others helping other to fill in the gaps. I let everyone down a little in that respect but luckily this is a great community of people who are all here to help each other.

[@pierrelebrasseur8493]

@@BurnDuration Question about excessive headspace; what reasons that make the headspace getting excessive?

[@billroberts9182]

Over 60 years ago my father had a hand load blow up the gun- it destroyed the gun and Dad lost partial hearing in one ear and had brass sprayed into one eye. A friend wanted him to shoot his new gun rebuild which was a fancy european with a metric designation. Owner couldn't find any brass for that caliber, so a Montana gunsmith loaded some shells. Dad went and talked to the gunsmith and found out he had taken .303 brass and turned the rim off of the case. In those days, the .303 brass had a folded "balloon head" or base (as opposed to the solid bases we have now). Many military actions have a large hole in the side to vent escaped gases in case there is a catstrophic case failure. Dad always warned me never to shoot someone else's handload! And I haven't. Thanks Dad!

[@FClassJohn]

Sorry to hear about your dad, that's horrible. And yeah, shooting others loads can be a recipe for disaster.

[@xnorcal831x]

I noticed it on some of my brass. I always wondered why. I haven't had a separation yet but I am glad you pointed that out

[@FClassJohn]

I'm glad you found it helpful.

[@metalifann42]

F-Class John and Erik Cortina. Professors in precision reloading. Well done.

[@FClassJohn]

Thank you for the kind words but I'm always learning too, so is Erik and so is everyone hopefully. This sport shows no mercy to those who know everything.

[@BoltActionReloading]

@@FClassJohn Possibly the best response I have ever seen sir. Truer words have never been spoken (cough, cough) typed. Great video.

[@FClassJohn]

@@BoltActionReloading Thank you.

[@mdell4959]

Excellent content! I’m a codger and we used a paper clip to feel for a line inside the case.

[@greggarmin9426]

Another good example why you should have a bore scope. Thanks for turning me onto Teslong endoscope.

[@FClassJohn]

No problem. Glad it helped!

[@terrydepew1252]

Early 90's i was curious how many firings a 30-06 case would last out of my 03 A3. Nice day at the range shooting off a bench i got 25 shots out of a new WW case before a fuzzy line appeared on the case wall. It wasn't the sharp scribed looking line like the one John showed but more like a faint blurry line. i was loading on the bench with a Lee Classic Target loader where a mallet is used to decap, neck size, prime and seat a bullet. Case was trimmed every load with the supplied trimmer and if i remember correctly trimming only removed just a smidge if any each time. Powder was a new tin can of IMR4350 (remember when powder came in metal cans?) and was measured using dipper method. Bullets used were 150 grn. Nosler ballistic tips and clocked around a mild 2450. Military factory loads with that weight bullet are like 2750 so you can see i wasn't stretching the case near as much each shot as max loads would have. Was poking holes in paper @ 100 yards that day and group size with that rifle was and still is right @ 1 inch. i wasn't done shooting after the first case test so i just used another new case or three until the whole 1 lb can was gone. Probably got just over a hundred shots out of that can of powder. i'm sure i still have them cases somewhere in storage. Now that i have a bore scope i need to dig them up and have a look inside. Lots easier than cutting one in half down the middle.

[@barrygrant2907]

I started reloading in the mid-'70s, and between you and Erik, I feel like I just started yesterday! Of course it doesn't take you guys' level of knowledge to reload a box of hunting rounds every year, but knowledge is power, and both of you have it in spades.

[@FClassJohn]

Very kind of you. I never feel like I'm that good, but I try to share what I know and if it helps then that makes me happy.

[@wilfdarr]

@@FClassJohn Moore importantly, you are sharing it with those of us just starting out. You are both so generous with your knowledge. Thank you.

[@FClassJohn]

@@wilfdarr you’re certainly welcome.

[@rickcaldwell6010]

Interesting video! I shot an M1 Garand (.30-06) in Service Rifle competition several years ago. The experienced shooters taught me to bend the end of a paper clip and insert it into a fired case, "feeling" for the bump that occurred if a case head was beginning to separate. It was a little time-consuming, but became a routine part of the reloading process and eliminated the possibility of leaving a stuck case in the chamber.

[@FClassJohn]

Yep the paper clip trick works great too.

[@timothybutler1]

Thanks for the video John. Very helpful demonstration of something to be concerned about.

[@FClassJohn]

Glad it was helpful!

[@Halfmilesniper]

Good info sir. I've not seen the signs on any of my brass, and I am always looking for early signs. Beautiful examples of pending case head separation. Great idea on using the borescope to check the inner wall.

[@FClassJohn]

Glad it was helpful.

[@markmuller3144]

One should be aware that your brass can take on a ring from moving around in your plastic ammo case, leading to a false reading.

[@FClassJohn]

@@markmuller3144 That's a great point and I totally agre. That's why I check inside (or like others have said you can use a paperclip or pic to feel).

[@HeavyChevy32]

Well I have watched ALL of Erik’s videos so now I’m over here 😂

[@FClassJohn]

welcome!!!

[@HeavyChevy32]

@@FClassJohn thank you!

[@tires2burn]

I just had a case separation yesterday in my 300 BO. The case looked like you cut it with a pipe cutter. Thanks to you I know how to identify a future problem.

[@FClassJohn]

Glad I could help.

[@johntandycrabtree392]

I own a surplus 6.55X55 Swedish Mauser. Killed my first deer with it at 7yo (I am now 59). The gun has extensive head space issues, so before each reloading, I made a feeler by straightening a paper clip and bending a small hook on the end which I filed to a point. By putting the clip inside the brass and scraping up the side, I can feel the beginning separation even before any visible signs on the outside of the brass.

[@RetrieverTrainingAlone]

EXCELLENT! Love the demos with your bore scopes! THANK YOU!

[@FClassJohn]

My pleasure

[@14goldmedals]

In the 1980's when brass tumblers were rare around my parts, I spotted those lines on the darker brass very easily as they looked quite white. The only brass I've ever had do that in 40 years of reloading was full length sized just a little too far 2 or 3 times at most. Sizing is everything when it comes to brass life unless you're a hot-rodder expanding primer pockets that is. Be safe.

[@paulleeper3188]

Outstanding video! I inspect my brass I feel very well but I don't load and shoot hundreds and hundreds of rounds and case head separation has been on of my worries. This explains it so there is no question what I am looking for. Thank you for the educational content of this video.

[@FClassJohn]

Glad it helps. Thanks for the kind words.

[@michaelmuzzy8401]

had this happen in 25-06 on a tc po hunter, I blamed hornady new brass 6 loads. I was new and didn't know better it was a head space problen. watching John,Eric,and Peit from Imact shooting I have learned ir you cant measure it or see it properly then you still don't know. The video was spot on.

[@FClassJohn]

Thank you for the kind words.

[@luigiderossi2901]

I have a Tikka t3x cal 223r rifle, and never had a problem so far! I have used commercial cartridges, few, and many carefully reloaded by me. Recently I was given some shells that had been used once on an AR 15. I reloaded them but three shells broke off. I checked the other cartridges and upon careful examination found that many had a ring about 2cm from the base. Luckily nothing serious happened, but in the future I will always use my shells and even more carefully, very carefully. Good morning

[@sunday8251]

Thanks for this info. I always thought that line was from the dies.

[@boydallen8059]

Probably the most important point is how to avoid incipient separations. Assuming correct chamber headspace very close management of shoulder bump (for all but semiautomatic) will prevent it. Your used brass was bumped too much probably more than once.

[@scotttracy2110]

I’ve been reloading 50 years, over that much time I’ve seen well over a dozen case head separation. Without exception they occur 1/4 of an inch maybe 3/8 above the base of the case. Never have I seen a separation midway up the case body. That’s interesting. Also all other photos I have previously seen of this problem show the ring around the case quite low. I just thought I would point that out.

[@frednurk4342]

As again very sage advice. The bin beckons. Thanks for your your generosity

[@laatjie]

I have had this happen in my 6.5-284 seems like about every 10 to 12 reloads. But I have never seen the cases on the inside. Thanks John

[@FClassJohn]

My pleasure.

[@planeiron241]

teslong borescope amazon for 55.00 cheap and very good pic

[@davidschmidt5810]

I’ve seen other videos where the same brass was used 20 times without issues. It really depends on many variables. There’s no magic number of firings. Thanks for sharing. Your videos are always very educational.

[@FClassJohn]

Glad you like them. As others have stated there’s various reasons but over-headspacing your brass tends to be the most damaging.

[@naps3386]

Are those other videos full-length sizing or neck sizing?

[@davidschmidt5810]

@@naps3386 “annealing test 100 yard group”. Check that video. Not sure how he sized.

[@memilanuk]

The trick... is being able to tell when it's a line indicating incipient case head separation... and when it's from getting dusty at some place like Rattlesnake - or Ben Avery - and then rubbing in the ammo box right at that spot. They look very much the same on the outside, before the brass is cleaned. Usually the 'Rattlesnake Ring' will buff out once you clean the brass.

[@FClassJohn]

Great point.

[@br4713]

A good indicator also that makes you guess it will happen is when you need to use the case trimmer too often. The shoulder has been pushed too far when resizing and when you shoot it again the case will get thinner and thinner (where it expands the more) until it makes this groove. When the shoulder is pushed too far when reloading the metal will be pushed out of the die by the neck and the case will get too long (need to get trimmed). The missing material is just the brass chips thrown in the trash when trimming 😅.

[@FClassJohn]

Exactly. That was very well stated.

[@planeiron241]

Good Vid John the Borescope is very handy for many things

[@FClassJohn]

Indeed it is. And I use it for all kinds of other household stuff that I don’t ever show.

[@DLN-ix6vf]

When the outside line becomes very prominent like the one in the photo and you run a sharp edge along the inside of the case wall and feel a dip all the way around the case then to be safe throw it out BUT you can still use the rest as brass does not fail evenly with every case. To know if the line is prominent on the outside run it over your finger nail and feel it. Just because one case has gone bad in a bunch doesn't mean the rest are bad.

[@raymondpeterson5748]

Thank you so much. I just did a bunch of brass and found several rounds like that after I full sized and created ammo. I've only shot them once (Starline brass) but I do think these were pieces that I put through the sizer a few times trying to set up my FL sizer. Won't make that mistake again.

[@Johnny-jr2lq]

Man that’s a gnarly line I believe if that was fired again it was going to separate for sure

[@matthewtracy8744]

I'm fairly new to reloading. This is great info that I never would have caught until it was to late.

[@FClassJohn]

Yeah a lot of people ignore the ring.

[@matthewtracy8744]

I'm all about doing things right. That's why I follow so many shooters. You and Eric Cortina have taught me soooo much already. This was my first season of long range, and I am now shooting 5" groups at 1000yds. So a big thanks to you sir!

[@FClassJohn]

@@matthewtracy8744 that’s very kind of you but it sounds like you’re doing everything right and the results are paying off. Congrats.

[@trevorkolmatycki4042]

The phenomenon is fatigue, not work hardening... also it is actually necking down from stretching as seen on interior borescope. every time you trim that material you remove is coming from somewhere it's stretching at the fatigue ring. Cool stuff!...

[@Roddy556]

Good video. I keep switching barrels and using different rifles so I bump a LOT, like 0.010" and with my latest barrel also need to use a small base die. I only get about three firings on Hornady brass.

[@stevereese6488]

Sign of fixing to have a bad day at the range. We had a factory load of 2506 separate, we sent the rest back to the manufacturer and they did us right. This was back in the 80s.

[@FClassJohn]

Yikes. Never had factory loads do it but glad you caught it.

[@linemen71]

Another great informative video thanks again

[@FClassJohn]

Glad you liked it.

[@madman432000]

My cases usually get that line closer to the case head, about half the distance that yours are.

[@FClassJohn]

Exactly ^

[@markmuller3144]

Yes, mine too. I have reloaded for over 50 years, umpteen thousands of rounds. including separations. always just above the head.

[@markmuller3144]

@@FClassJohnI please explain to us how the higher than typical separation is effected by how you size it. my experience has all separations just above the head.

[@FClassJohn]

@@markmuller3144 I don't disagree that it's weird. I also have seen almost everything happening lower on the base near the head. My caveman theory is that somehow the particular barrel he had was chambered just a little different combined with his custom reamed dies led to a situation that either work hardened that part of the brass or caused it to stretch in an odd way. Again, just a theory and I certainly don't know everything so it could be something completely different.

[@rudolphferdinand3634]

It is a problem for 30-06 cases, so I learned by taking a paper clip straightened then ‘L’ shape near end and sharpen to a point.

[@davidhutchinson6108]

Now that was a helpful video. Thanks John!

[@FClassJohn]

Glad you found it helpful.

[@richardcollin3695]

Thanks John, excellent information I will be keeping a lookout . Cheers

[@FClassJohn]

Glad it was helpful.

[@bloke3006]

Thanks John, that was prue gold!

[@FClassJohn]

Glad you found it helpful.

[@kbob871]

I started reloading in 1966 for my dad i loaded shotgun shells for his hunting then in 70 for my brother that was brass he competed lots the only time that i have seen case separation is when i set the shoulder back. as long as the neck is sized and the shoulder is just kissed separation is never seen i have had cases that i have reloaded 28 times with max charges they can get so thin that you can see through them but they still hold a round.

[@jmkhenka]

Depending on caliber you can use a flashlight and see a ring on the inside, or really a shadow. I had a case that got 25% or so separated (ejected fine but it had some flashthrough). So i took some other cases from the same session and a flashlight. Lo and behold, 5 more of the 30-ish cases had visible rings inside. You can feel them with a metalic pic. Just to make sure, i took one of the cases and cut it in half and then it becomes really apperant. They would probably held for a firing more but why take the chance. this was 6.5 Grendel hornady cases with 10-15 firings. I could see on the worst cases a ring on the outside to, a couple mm above the marks from the FL die. now i always check them before reloading, if i cant see anything they should be safe.

[@FClassJohn]

Sounds like you have a good process to prevent problems.

[@tommykawasaki9676]

I had case head separation twice. Once the remainder of the case popped right out of the chamber with a rod & brush. No sweat. Once it did not & for all my trying, I couldn’t remove the rest of the case from my chamber. My local gunsmith had to go to great lengths to remove it & it cost $50 to get it out. See a ring, toss the lot. I no longer try to milk all the mileage I can, from my cases. Not worth it. In a competition setting, I would have been done.

[@dbmail545]

I just purchased 200 rounds of reloadable brass 5.45x39. Guess I get to learn to reload now.

[@leoburns9674]

Best video on the subject... very helpful, thank you!

[@FClassJohn]

Thank you. Very kind of you to say.

[@Rick-hx1ne]

Stretch the cast shell it good to see the microscope that cool how thin the wall is and know it can't be used again it may have little headspace in your rifle it could be worn a little bit ?

[@Derecq]

I had a couple of case separations shooting a match in September, I was using Federal nickel plated .223 which had only been reloaded a couple of times. Fortunately the cases extracted but my safety supervisor thought for a moment I was shooting 9mm when the case head fell out the rifle. Looked at the rest of my rounds from that batch and didn't shoot them.

[@FClassJohn]

Probably a smart thing. Glad everything was ok.

[@Blanchy10]

Can be caused by excessive head space too. I had a 243 that if Full length resized would show those signs after a couple of reloads.

[@FClassJohn]

Yes headspace for sure as well. In fact headspace is most often the major cause.

[@TexasTrained]

A friend if mine got this line on 2nd firing on his 223 Ackley Improved new barrel.

[@genedavis759]

It looks to me like the place where the case thickness transitions from thicker near primer end to thinner up to shoulder. I've cut casings lengthwise in half to check on brass flow from many firings to see what's going on and about where you showed groove is the top of that thicker base wall thickness. Which to me would indicate a flex differential when resizing and firing.

[@Wheelchair-bear]

I have some once shot hornady precision Hunter brass 6.5 PRC and the ring is showing up already, once fired. I have this problem with about 40% of the brass of that same make. Very frustrating! I don't even know if I can reload it one time.

[@glockparaastra]

What calibre is that? Good info. A paperclip stretched out with a little 90 degree hook at the end is also a good way to check. Insert it and feel for that trench.

[@FClassJohn]

Yeah the paper clip trick works great too. I’ve done it plenty of times as well.

[@josephlapierre3407]

What's about to happen is you're about to have to cut your day at the range short and go home and get the other 3/4 of your case out of your chamber! Been there, done that. Back before I understood the importance of proper headspacing. Was bumping my shoulders back too far when I was sizing the cases and overworking the brass.😂

[@lohikarhu734]

John; I have been poking away at papers on annealing, and it appears that there is a nasty thing that appears at about 200°C, a kind of hardening before softening...it could be that the separation line occurs at a point where the work-hardening due to firing is "meeting" the annealing, near where the brass reaches that temperature while the neck is annealing? Maybe, just a maybe, one needs to ensure that the case remains cool, or that annealing actually extends to nearer the 'base', avoiding softening of the head, but allowing some degree of annealing further down the case? But, just extrapolation from some scientific papers....

[@FClassJohn]

When it comes to case head separation the real culprit is case stretch from brass where the shoulders were pushed too far back. While annealing can help with other factors in brass life, proper sizing is the only thing that will really keep this from happening. Check out my other video I did after this on what's causing case head separation.

[@JayKayKay7]

I thought case head separation risk sequence cycle was the following. Hot loads leading to brass elongation exacerbated by excessive resizing leading to case wall thinning just ahead of the case web and excess trimming to restart the cycle until catastrophic failure. Rinse and repeat 9 or 10 times and I think you got your money's worth out of that case.

[@bunnykiller]

9 times?? wow... I usually retire mine after the 5th time even if it still looks ok, by then Ive got my monies worth out of it. I will even throw the used brass ( 4 times fired) if its showing sizing wear or it gets about .001 out of spec near the base, also, if it sticks in the OAL tester it gets put into the bag to be melted down ( I make paper weight discs out of the old brass).

[@brianmccutchan9513]

Excellent video !

[@FClassJohn]

Thank you.

[@andrewspilberg5023]

I am seeing a similar faint line on new production 338 Lapua Magnum commercial match ammunition (not LAPUA brass). It's about 1/4" from the base of the brass. When I pulled the bullet and emptied the powder I could see, with a borescope, what appears to be a ring shaped "crack" on the inside of the case. I was intending to reload it but it may not be worth the risk.

[@FClassJohn]

Yeah you never know when it will fail.

[@bigracer3867]

Heard the trick bend a paper clip to a angle small enough to go in case and run it down inside to feel any separation starting. Even before any evidence on the outside shows.

[@FClassJohn]

Yeah that's a great trick and always works well.

[@williebulletman5217]

Great information sir

[@FClassJohn]

Thank you.

[@kyley808]

As always awesome information thanks

[@FClassJohn]

Glad it helps.

[@m3rcynside458]

Wow, very interesting. Great video!

[@FClassJohn]

Thank you!

[@MegaPoxie]

If your headspace is wrong, I've had cases look that bad and even separation after as little as 3 reloads. I always thought it was the brass flowing away from the thicker base portion, that point where the body thins and that flow pushes the shoulder and neck up, requiring trimming. Can you hacksaw a case down its length to show the weak point?

[@FClassJohn]

I also agree that over head spacing can contribute to it as well and I appreciate you posting this. It’s almost almost a combination of things that cause these issues and it’s always still amazing to me how everything we deal with is on such a micro-precise level that throwing one part off just spoils the punch.

[@pierrelebrasseur8493]

Chamber grows as round are being fired and need to be set back from time to time.

[@mikeq7096]

Very interesting.. Wondering what you are using to look into the brass?????

[@FClassJohn]

Teslong borescope. Here's a bunch to choose from amzn.to/2UvXILW

[@jeffmorrow1957]

Was the line not visible until after you tumbled the brass?

[@shotgunmatt1]

Do you think stainless steel tumbling makes the external signs harder to see?

[@tjgrossman]

Couple of questions: Do you size with a body die or a FL bushing die? Is that 6.5-284 or 6 Shehane? Thanks.

[@tv-cx8gv]

Good video.

[@FClassJohn]

Thank you

[@amirdzaferovic3489]

Great Video!

[@FClassJohn]

Thanks!

[@rungun3982]

I personally learnt this the hard way using 3xfired brass. The reason why I think was because of an error in bumping the shoulder 7 thou instead of 2. Also I chucked the whole batch why take the risk on compromised brass

[@FClassJohn]

Yep. As others have started, over bumping is definitely a major contributor to this happening. And I just sucks when it happens because it’s one of those conditions where you can’t do anything to fix it once it happens.

[@rungun3982]

@@FClassJohn glad I learnt this lesson on Hornady .223 Match ammo I fired then harvested the brass. Made the decision to bin very easy. Off topic why do Hornady put a crimp in there primer pockets?

[@FClassJohn]

@@rungun3982 I honestly have no idea on the crimp. I’m familiar with them really.

[@rungun3982]

@@FClassJohn I was heading towards Lapua brass anyway due to recommendations and now I have used it I wouldn't use anything else for best loads.

[@michaelmuzzy8401]

@@rungun3982 same here

[@sawekmarat3055]

Beautyful picture.😉

[@pierrelebrasseur8493]

You followed Eric Cortina advised... can you explain why you got head separation and / or rings?

[@FClassJohn]

I was inadvertently pushing shoulders back too far.

[@benweeks304]

I know it would be hard to measure, but I wonder if the width of the line correlates to the same number as the shoulder bump. For example if you set back the shoulder .0015. I wonder If the line is also .0015.

[@tims.9883]

What kind of a headspace guage is that? The box label says "Mitutoy"? Also, what do you consider match brass? Is it anything that doesn't have case head separation or is that just one of several criteria? Does the brass have to be brand new?

[@FClassJohn]

That's the Hornady but I upgraded a few years ago to the Short Action Customs. They're amazing and so repeatable it's crazy shortactioncustoms.com/product-category/headspace-comparators/. Match brass would be something like Lapua and any brass can have case head separation.

[@tims.9883]

@@FClassJohn so match brass is much more accurate than lesser quality brass?

[@rdsii64]

When I first see the faint line, would I be safe to toss it after the next firing?

[@FClassJohn]

I couldn't say. I've shot faint lines with no issues and other times had separation. Do what feels safe is the best thing. I tend to lean on ditching brass for several reasons but everyone is different. For one I rather have the best brass to test or shoot (unless I'm testing something weird that doesn't matte) and second I just don't like risking a separation if I can help it.

[@terrycostakis6284]

I run a stainless steel dental pick through the inside of my brass and I've never found a case in which I could feel an indentation warning of a pending case head separation but much of my brass has a similar appearing ring much lower on the body, almost to the case head. I noticed that the bad cases you showed had the ring much higher up the case. Is that a general rule of thumb as to the location of the separation and that a ring almost all the way down to the case head shouldn't be a concern?

[@FClassJohn]

I’m not sure there’s an ‘absolute’ in this situation. It’s not a regular phenomenon that occurs so I only have mine and others data to work with. I’ve seen rings form in various places and I’ve had separation at different levels which leads me to believe it’s a function of your sizing die combined with how much you’re bumping and probably some other factors that I have no idea of.

[@qedsteve]

Is there a broken case extractor you can recommend for 6.5 PRC? My googling can't seem to find one except 6.5 Japanese.

[@FClassJohn]

I’m not super familiar with broken case extractors. I’ve been fortunate enough that when this happens I just run an oversized brush or bore mop on there and it’s come out.

[@SkypowerwithKarl]

You normally see this closer to the head. Yup, time to chuck them.

[@ocean374]

Great info thanks for sharing What size camera you are using or brand thanks

[@FClassJohn]

It's the Teslong WiFi borescope.

[@ocean374]

Thanks

[@billroberts9182]

Two Questions 1. What happens if the case completely separates while firing? 2. Brass doesn't have intrinsic strength- I've always been told it expands to fit the chamber and bolt face- so why not anneal the whole cartridge? (and not just the neck)

[@FClassJohn]

1)You pull the pieces out and evaluate the rest of your loads and go from there, at least in my experience. 2)Yes it does but I don't honestly know the answer to why we don't anneal the whole case and don't want to give any information that may be false. I have educated guesses but that's all they'd be. All I know is that it's never done and there's a god reason, so I'll see if I can ask people smarter than me to find out why.

[@Antonio-j1g]

What about when the round line shows at the neck of the brass?

[@allanmoffat5015]

I have once fired brass a similar line 1/3 down from the shoulder showed up after full length sizing, do case head separations happen so high? I am wondering is this likely caused by the dies?

[@FClassJohn]

It depends. If it's right after sizing then yes. If it's after you've been shooting then it's a wear mark from the ammo box which can happen if the hole for your ammo is round.

[@johanswart8116]

I have have a paperclip i bended so i can feel the ridge in the case. So i check it. I reload a 303 britt also. If you get to reload the brass 5 times your lucky. Lol

[@FClassJohn]

Yeah you can't be in this sport and try to be cheap when it comes to this stuff. Sounds like you know when to get new brass so that's good. Better accuracy and safe for sure.

[@impactaustria]

Do you usually see a line OUTSIDE before riskinga head seperation on the next firing, or do you have to use something like a wall thickness measuring tool to make sure your brass is about beeing done?

[@FClassJohn]

In my limited experience from my own and others issue I would say the line shows up most of the time however I have no doubt that you may see or feel a line inside without a clear line outside. Also, maybe I misunderstand the question but I don't think you'd be able to get a wall thickness gauge into the body.

[@impactaustria]

@@FClassJohn Not the typical wal thickness gauges or ball micrometer, like those you use for neck wall thickness, but there are tools capable of mesuring wall thickness down to the base/head. Like the bent needle on the RCBS case master gauging tool. When you index and zero the micrometer on it's tip, you can get measurements way beyond the neck. Of course it's not that precise and it's a little tedious, but should be no problem to identify thin spots like those shown by you with the bore scope. A bore scope might be more convenient though, if problems use to show up as pronounced as on the case shown in you video, but putting a number on it can also help. Btw, thanks for sharing your experiences, methods and thoughts!

[@robertsherrick6276]

So how do you fix it so it doesn't do that anymore??

[@richardthomas6602]

Newbe question: why doesn't the heat from firing the cartridge anneal the brass?

[@FClassJohn]

Simple answer as I understand it is that it’s not hot enough for long enough. It’s more complicated than that but at its core that’s why.

[@skytrooper506]

Can I ask what type of scope you're using to look into the cases?

[@FClassJohn]

I use this one amzn.to/3TQ3kye but they make a lot of different versions that all work really well.

[@nt_wicked_bunch2717]

I’ve had a few separate but never had one completely separate from the head. Have you ever had that happen or have you seen it? I bet that would be a huge mess.

[@FClassJohn]

I’ve had it happen and it’s not that bad in terms of a mess. The few times I’ve had it happen the brass came right out although I’m sure u see different circumstances and guns the result could be worse.

[@timg6252]

Hi John, I've been looking at this issue lately. I've only ever had 1 chamber produce seperation, a 6.5 SLR that I ran hard and only 5 of 200 cases. You mention that it's caused by sizing. Is that an educated guess or are you sure? The reason I ask is bar the initial resize from 308 to 6.5 I used a Lee collet die so never sized the body. (Don't tell Eric). I've heard of a few possible causes, just want to try and ID the actual one for everyones benefit.

[@FClassJohn]

Best I know (and I don't know everything) is that excessive shoulder bump is the main culprit. I do however feel (and I could certainly be wrong) that body sizing has some effect as does how the brass fires in the chamber (but to a very small degree). But keep in mind that if you can trim your brass then you're losing brass from the base to some degree and it adds up over time. And don't worry, I won't tell Eric.

[@timg6252]

@@FClassJohn Thanks John, I have a theory that fl sizing is in play here but not the "cause". I was thinking excessive head space on initial fireforming, but on F class guns??? Just not happening. As someone else mentioned, I noticed your seperation is way further up the case than I've seen before which may be laying another possibility to rest. It looked like the inside of those primer pockets were chamfered. I don't suppose you know what tool was used?

[@FClassJohn]

@@timg6252 I'm sorry I don't. But I like where you're going with this...

[@timg6252]

@@FClassJohn I was doing some high speed filming of primers and ran a chamfered pocket through the test. The flame front is a completely different shape (well it's meant to be, that's why some folks do it). It just struck me that the angle of the dangle meant the flame front would hit the case wall right where case head seperation (usually) happens. Your case stuffs that theory up a bit unless the chamfer was done with something 'unusual', but I'll persue it a bit more.

[@rotasaustralis]

Damn, I gotta get me one of them borescopes. I'm still scratching around with the ole sharp piece of wire with a 90 Deg bend on the end. Great vid John Regards........Rotas

[@FClassJohn]

Thank you.

[@AlecksACe]

Does too much shoulder bump the only reason for case head separation?

[@FClassJohn]

I’m not a metallurgist but I’m going to say that it’s one of the major contributors but not the only one. I’ve seen brass bumper hard never do this and lightly bumped brass do it so in my mind there’s a combination of bumping and other factors that accelerate this condition.

[@robertcope9494]

I thought this came from headspace issues. Is there a lower separation of the case from headspace issues?

[@FClassJohn]

Yes from headspace. I did a poor job of explaining that part as I was more focused on showing the actual brass issues.

[@duggydo]

John, have you ever had brass separate in the chamber? I can imagine it might be difficult to get out.

[@FClassJohn]

Yes I have and it really isn’t that bad although it does affect your shot for sure which is why I’d never risk it at a match if I can help it. Under different loads in different guns the result could always be different of course.

[@rungun3982]

When it happened to me I used a brass brush on my rod to push it back out

[@Chainspike101]

what borescope are you using?

[@FClassJohn]

It's this one amzn.to/3OwIEHD but they make a variety of them so see which one might fit your needs best.

[@justinvandee2008]

Have you noticed if the streaks/channel on the inside of neck effects accuracy by making scratches on bullet?

[@FClassJohn]

Anecdotally yeah I’ve seen some light marks if I seat a bullet and them pull it. Thats also why I used to bronze wool my necks (a practice I’m starting to do again).

[@justinvandee2008]

@@FClassJohn did you do a video on that? I have some virgin Lapua brass that had like a ridge at base of neck. When I ran carbide mandrel it left tiny amount of brass on mandrel. I did not notice till all was done and went to seat bullet. Seated one and pulled bullet. Scratch jacket

[@FClassJohn]

@@justinvandee2008 Yeah it's old. One of my first brass prep videos. The brass wool was part o the video.

[@tunafish3216]

I check every round with a paper clip on the inside you will find them before you see them.

[@FClassJohn]

Yeah that's a great tried and true method.

[@davidhoward4609]

When I fl resize my brass actually grows by about .0015 does that mean my headspace is off, it still chambers fine and my die is touching the shellholder

[@FClassJohn]

I've seen plenty of times where a die isn't pushing the shoulders properly (hence the growth) and the die needs to be shortened as little. I usually have my gunsmith throw it in the lathe and shorten them a hair depending on my needs.

[@davidhoward4609]

@@FClassJohn thanks for the quick reply, I actually work at a machine shop and custom gun shop Kauger Arms, again thank you

[@FClassJohn]

@@davidhoward4609 No problem. My assumption is this condition is brought on with custom chambers compared to SAMMi spec dies.

[@gilream]

...doesn't this mean that this guy is bumping his case shoulders back too far.? Of course he is! does he mention that in this video? No he doesn't. Ive been reloading for 35 years and I've never come close to having a case head separation. I loaded well over 3000 rounds last year.

[@TXH1138]

Do you think case head separation can happen on brand new 9mm?

[@FClassJohn]

I specialize in rifle brass and haven't loaded pistol in decades and don't want to give you bad answer. In theory, any piece of brass can suffer case head separation but I'm unsure of what conditions need to exist for pistol brass vs. rifle.

[@TXH1138]

@@FClassJohn thank you.