A few weeks ago maybe a month or more, when I was at the range picking up my brass I saw these.
These cases I found have mega cracks on the necks. Below are photos of these cases.
If not bad head space or timing for the rifle these could serve well as a warning to new hand loaders to keep a eye for excessive pressure.
I can tell you by way of pattern and location of the cases it was a auto- loading rife. Infront spread off the the right. Which is why I also think it could be bad head space or timing.

probably work harden brass.
Do you know what they were shot in?
I had some come out of my garand that looked alot like those.

Were those cased hardened, factor, or mil surplus for your M1? I never had cases pop out like that. I enjoy my 1903A3 a little more.
But I can see these cases were reloads. Almost never have splits in my cases in such quantities. Thats why I wonder about the head space or timing of the action.
Corse then again if I knew who was shooting them ....

But alot of people love to load hot too. I know of a guy who will sometimes need to kick open the bolt. Needless to say I dont shoot with him anymore.

Shooting such loads dose not help accuracy but opens your groups. Its pointless to push a .308 DIA bullet at 3k if you cannot hit anything.

they were rem brass once fired 168gr bullet loaded with imr 4064 to about 2600f/s. normal load I still shoot it using that load.
I thought I may have had a problem with the chamber but after firing some other loads every thing was normal. the M1 chambers are liberal or maybe a little on the large size anyway.
It 1943 springfield in 30/06

I had some neck cracks with some 30 yar old 308 mil rounds.Out of 40 rounds a third of them cracked like those were.After a little work with a torch they reloaded fine and have been shot about 7 times.Good Luck

It looks to me as though they were old brass , reloaded with out annealing necks cracked as a result of work hardening .
IMO .

Mil chambers are lose and some people use small base dies unnecessarily ,when resizing with hard brass results are as shown .

What's the head stamp say on those James ?. I've also seen that very problem when someone gets brass from someone else , then sizes it reloads it full tilt and it goes BOOM and that's all they cared about .

Those look like cases I dumped, but wrong part of the country.

I believe the surplus powder I loaded in my cases is outgassing so much nitric acid gas, that my case necks are cracking.

It has happened to me before. Old powder will cause neck cracks on firing, then the necks will crack in unfired cases.

quote:

Old powder will cause neck cracks on firing, then the necks will crack in unfired cases.

Is that from powder gases or is it simply age hardening and stress corrosion cracking? I know old misurp 303 Brit brass does that. Those cases are sealed with butimen over propellant wads and the bullet is seated in butimen too. I had a batch of 303-25 cases cracking like that on firing. These were factory loads. I pulled the rest, annealed the necks, reloaded and had no more cracking. This makes me think it is age or work hardening rather than chemical weakening.

Brittle Brass - Stress corrosion cracking from ammonia or coming in contact with vinegar, making the brass brittle. Annealing will not correct this if caused by a chemical. Plus unsupported brass in the chamber if the fired case necks measure larger than .343"(30-06) will cause vertical spliting

A completely different scenario ; Chemical corrosion VS work hardened or vertical splitting as opposed too Radial separation .

I've also had brass separate radially from a head space problem , although that is NOT COMMON as far as I KNOW .

Belted ammo separates above the belt upon repeated stretching or firing as well as improper sizing or

improper chamber dimensions .

Maybe AC; will weigh in as he is very knowledgeable about such thinks .

Doc-

Thanks, but I'm sure you know as much as I about brass and ammo.

One comment I will make - probably the most common cause of that kind of cracking is purely and simply ageing of the ammunition AFTER it is loaded.

Because the internal diameter of the case necks is smaller than the external diameter of the bullets, loading the bullets into the case necks places the necks in a condition of stress.

We recognize that as "neck tension" on the bullet, and it is a required situation for military and sporting ammo, to keep the bullets in place during handling and chambering....and to help the powder burn as designed.

That stress, over time, tends to harden and eventually crack case necks. I have salvaged components from case-lots of older ammo, every single round of which eventually cracked during storage. (A common name for that kind of neck-splitting is "season-cracking".)

(For instance, I got my life-time supply of Cordite powder back in 1970 or '71 by salvaging it from Kynoch .416 ammo, every single round of which had cracked necks which occured during storage and without any of them being fired or reloaded.)

With ammo made in time of war, the problem occurs faster with some lots of ammo than with ammo made during peace time, simply because allowed tolerances are greater during war production, and the final annealing before loading may not be done quite as well either.

Anyway, I suspect the necks of the cases you picked up could have been "stress-hardened" simply due to age, and need never have been fired or reloaded at all. Once they were hard enough from years of tension, they were ripe for cracking, though not "ripe-enough" for them all to crack.

Like everything else in reloading though, lots of other possibilities exist. If they had been old, then fired, and then reloaded without annealing, such cracks due to hardening are even more likely.

I apologize for all my typos, but I have no spell-checker which will work at this site, and my vision has been getting rapidly worse since my stroke.

Edited the "morning after" to add:

Am not suggesting those cases didn't crack on firing. They probably did. Was just trying to say that some of them could have been reasonably expected to crack if they had been stored a long time after being loaded. Stress hardened cases often crack on the first firing.

quote:

I apologize for all my typos,

Alberta Canuck, you may make as many 'typos' as you wish! Just keep the wisdom coming!

I'm sorry to learn you've had a stroke. Do take care!

Thank you, 303Guy. I appreciate your civility.

BTW, have added a paragraph at the end of my above post, to clarify it a bit.

Here's the addition:

Edited the "morning after" to add:

Am not suggesting those cases didn't crack on firing. They probably did. Was just trying to say that some of them could have been reasonably expected to crack if they had been stored a long time after being loaded. Stress hardened cases often crack on the first firing.

I agree with that 100% !. Because it's not only happened too me but Old WWII ammo I've fired almost everyone cracked as the lot was 1943 I believe and rumored to have been Africa Corp surplus .

No way for verification as it's LONG GONE now !.

I m still here and alive, just reading the posts. Thanks for all the good info too! Good to hear AC is doing better!
See this is a topic I m not all that knowledgeable about apparently. So I m soaking it all in.

quote:

Originally posted by Alberta Canuck:
I apologize for all my typos, but I have no spell-checker which will work at this site, and my vision has been getting rapidly worse since my stroke. ...

"A man has a "limited mental capacity" when he can only spell words one way!"(or words to that effect) - Mark Twain