308 Case Necks Splitting

When I quit competing in NRA across-the-course High Power rifle matches almost 20 years ago, I had several hundred loaded cartridges of various loads and just left them in my reloading shed. All 308, mostly loaded with 168 Sierra BTHP, 40.5 gr of 4895, Win primers, Federal brass. Bolt gun, rapid fire ammo. All twice reloaded, full length re-sized in between loadings. All always shot in the same bolt gun. The gun's chamber measures "0" and I was resizeing to "-.002".
I decided to put my target scope on the bolt gun and do some informal target shooting. While at the range and in the process of sighting in the scope I shot seven rounds without looking at the fired brass, only concentrating on the target and scope. As I took the eighth round out I happened to glance at it and the complete neck was gone. I then examined the preceding seven and on each the neck had split lengthwise all the way from the mouth to the shoulder, some had two splits. Some had also split horizontally partially around the neck/shoulder juncture. Luckily when I raised the muzzle of the rifle the missing case neck fell out of the chamber.
I have loaded and fired many thousand rounds of this same load combination and never has so much as a misfire. The only variable I can think of is the ammo being stored in an uncontrolled environment for almost 20 years.
Has anyone had a similar experience or any thoughts on what might have caused this?

just my thoughts on this but sounds like the bullets are stuck to the case neck. not sure what is is really called but it is when two metals bond to each other thru some chemical reaction over time. it could also be the brass has become brittle over time some how but i would go for the first one. you could try to break the bond by seating the bullet a few thousands before shooting and see how that works.

gary

Earl39
Thanks for the reply. The brass ageing may be a percentage of the problem. I did however get a very extensive and informative reply on another forum, about the effects of heat on powder, both in loaded rounds and still in the factory container. The individual had experienced almost the same conditions as I. He quoted both military literature and Alliant responses to his problem and it boiled down to this; Heat causes the powder to deteriorate and give off gases. These gases weaken the brass to the point that it becomes brittle and cracks, either during the firing of the round or in worse conditions while the round is still in the box. I don't know if this forum allows links to another forum or I would post a link to his response. This problem took me quite by surprise but it is a condition that EVERY reloader should be aware of. Store Your Powder In A Cool Environment and be leary of old powder, even if still in the factory container.
Again, thanks for your response.
Boweevil23

Quote:

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Originally Posted by boweevil

Earl39
Thanks for the reply. The brass ageing may be a percentage of the problem. I did however get a very extensive and informative reply on another forum, about the effects of heat on powder, both in loaded rounds and still in the factory container. The individual had experienced almost the same conditions as I. He quoted both military literature and Alliant responses to his problem and it boiled down to this; Heat causes the powder to deteriorate and give off gases. These gases weaken the brass to the point that it becomes brittle and cracks, either during the firing of the round or in worse conditions while the round is still in the box. I don't know if this forum allows links to another forum or I would post a link to his response. This problem took me quite by surprise but it is a condition that EVERY reloader should be aware of. Store Your Powder In A Cool Environment and be leary of old powder, even if still in the factory container.
Again, thanks for your response.
Boweevil23

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You could say you Savaged our forum at http://thefiringline.com/forums/showthread.php?t=429270

"By the way, I had posted this on another forum, had many views but not a single reply. I KNOW what forum I'll put confidence in from now on."

Boweevil23

bigedp51
I hope that you and the entire forum will accept my sincere apology for disrespecting your forum. You have a well well run and very informative operation and I have spent several hours reading posts that I was interested in.
I had what I considered to be a dangerous situation and was hoping to get a well informed answer to my inquiry. When I got no response I posted on the other site and got my answer in just a few hours.
I let my mouth overload my butt and made a stupid statement.
Again, I'm sorry and hope I will be welcome to post again here.
Boweevil

You can seat the bullets 0.002 to 0.005" on a few rounds and try to shoot them again.

Will break the bond to test which possibility exists on your rounds.

dcloco
I just now reseated several rounds and all made a distinctive "pop" when the bond broke. Can't get to the range until next week to test them. Will post results.
Boweevil

Went to the range with the reseated bullets. Tried three and all three split.
I had also freshly loaded twenty rounds, same leftover brass as the problem brass, same componets etc; shot all twenty and had two to split slightly.
My conclusion is (possibly in error) that this brass was not annealed sufficiently during manufacture. As long as I was actively reloading it, over a short period of time, it functioned perfectly (I would normally chunk the brass after five reloads). After aging 17 years the brass became brittle, the loaded cartridges with the bullets in place were under strain in the neck and deteriorated more (100% failures) than the empty brass (two out of twenty failed).
The deteriorating powder could be a percentage of the problem but since I also had the two splits in the 20 freshly loaded rounds I don't think that it is the primary problem.
Didn't think of it before I went to the range but I have some leftovers loaded in Lake City match brass and also some Lake City White Box match factory loads. I'll try them next trip and see if they also have this splitting problem.

Quote:

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Originally Posted by boweevil

Went to the range with the reseated bullets. Tried three and all three split.
I had also freshly loaded twenty rounds, same leftover brass as the problem brass, same componets etc; shot all twenty and had two to split slightly.
My conclusion is (possibly in error) that this brass was not annealed sufficiently during manufacture. As long as I was actively reloading it, over a short period of time, it functioned perfectly (I would normally chunk the brass after five reloads). After aging 17 years the brass became brittle, the loaded cartridges with the bullets in place were under strain in the neck and deteriorated more (100% failures) than the empty brass (two out of twenty failed).
The deteriorating powder could be a percentage of the problem but since I also had the two splits in the 20 freshly loaded rounds I don't think that it is the primary problem.
Didn't think of it before I went to the range but I have some leftovers loaded in Lake City match brass and also some Lake City White Box match factory loads. I'll try them next trip and see if they also have this splitting problem.

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My sneaking suspicion is the annealing....I think you're on to something there!

Wayne

I've got Lake City 71 308 Match brass that still shoots well and has never had a split. It was stored in my son's garage in 07 while I was in Afghanistan. It didn't appear to suffer being stored in temperature extremes for almost a year.

A friend had some old 20 year old Federal factory loaded 30-30 ammo that did the same thing. 80% of the cases split. A reason the military destroys out of date ammo???

Go figure-I shot a few rounds of WW II 30-06 AP ammo the other day doing a test. Brass was fine, LC 43 headstamp? Didn't look until this post will prompt me to. Reloaded it, with some other brass, mostly LC 73 Match and it all shot OK. I really felt that had the "seal" been broken by a quick run thru a reloading die, the brass may not have cracked. I say this because when I left the military, as an MP and Rifle/Pistol team coach, I had access to a lot of mil brass and ammo. A lot of my hunting ammo was LC 7.62 with lacquer seal cracked in a reload press, the bullet pulled and a quality 150 gr. HPBT from Sierra reseated.

Some of the best ammo I ever shot from my .308 was LC63, not reloads but origional stuff. It was stored in the basement of my grand parrents house for 20 years and then in the attic of my parents old house for another 20+ years with no temperature control. 110 degrees in the summer and -30 in the winter. No case issues and I reloaded that brass 2 or 3 times after that with no problems.