cracked case

[whitbyman]

After firing my 300 WSM, I noticed one of the cases, out of 20, was severely damaged. All rounds were Federal factory loads. The crack were at the neck five of them all vertical. I would expect something like this out of a reloaded case where the neck has weakened but not out of a factory load.

Has anyone see anything like this before? I wonder if I should contact Federal and let them know.

have a look

thanks

 

[AP]

Did you leave some Sweets 7.62 in the chamber ... a high concentrate ammonia will cause brass to do this if allowed to ... happened to me till I figured out why..
just a though fwiw

 

[Breaker61]

Never had that happen with a factory rifle round, but 9mm pistol is a different story. Purchased 10 boxes of Federal American Eagle 9mm all with the same lot #. Five casings split out of one individual box of 50. All other casings were fine. E-mailed Federal, never got a response.

 

[ErikT]

Had the same thing happen to me in a couple rounds of 7mm WSM, but these were all virgin Winchester brass that I reloaded myself. Upon closer inspection, the damaged brass each had a small wrinkle at the shoulder, as though they hadn't formed them properly. This wrinkle must have wekened the brass at that point, causing it to burst on firing. I've never had it with any other cartridge, so maybe it's part of the charm of the WSMs?

Erik.

 

[whitbyman]

Did you leave some Sweets 7.62 in the chamber ... a high concentrate ammonia will cause brass to do this if allowed to ... happened to me till I figured out why..
just a though fwiw

I didn't notice the case until I collected the brass at the end of the shoot. If this was the first case fired, then a dirty chamber might explain the damage.

 

[AP]

Well if it is ammonia - then that is preventable. Apparently the ammonia reacts with brass to make it brittle . I was getting similar case splitting around the shoulder/neck area just as you illustrate. It stopped when I was more careful to wash/dry the chamber carefully after using Sweets (particularly high ammonia content - really clears the old sinuses) . If you left a little residue in the chamber and the first round sat for a while that might be the problem. Warm water - better yet boiling water - really clears it out and if the metal gets real hot from the water it dries pretty quick.
A couple of dry flannel patches and lightly oiled one is all you need ... just don't leave the chamber oily when you plan to use it. There is a view that this can cause the case to place too much pressure on the bolt face if the chamber is oily.

 

[tigrr]

This happens all the time with factory ammo. Some the shoulder splits like yours did and some the necks split. Some have such a loose primer pocket after the first firing, that you can seat the primer with your thumb. In the last 30 years I have probably seen 50 rifle and shotgun cases split.