Guys - I am a brass whore, meaning every time I go to the club I spend my first 30-60 minutes picking up other peoples brass that they left laying on the ground.

Today I found about 25-30 pieces of 7.62 x 51 (308 Win.) brass that shows to be Lake City military brass and the majority I picked up and then ended up throwing away is reflected in the photos below.

What would cause this to occur on so many rounds?

Most likely work hardened brass. If the cases had been reloaded a few times the necks could need to be annealed.

WOW! That's very uniform in all but one case. Almost looks deliberate but why?

In my experience, hardened brass will split from the case mouth down towards the shoulder. No idea what might cause this.

RMD

This message has been edited. Last edited by: rduckwor,

Looks like a lack of annealing perhaps?

I'm just guessing, but over-aggressive neck turning (cut too far back or too deeply)? Shoulder set back too far? Flaw in the chamber? Any of the above combined with work hardening, maybe?

Work hardened brass.

I had an 8mm Mauser that did that to some ammo I got with it.
After the first five, I went home and pulled the bullets, powder and primer on 5. Annealed them and reloaded them, no issues.

quote:

Originally posted by Expert308:
I'm just guessing, but over-aggressive neck turning (cut too far back or too deeply)? Shoulder set back too far? Flaw in the chamber? Any of the above combined with work hardening, maybe?

I think you're right on. I'd be willing to bet if we had access to the rifle that fired those and a borescope, we'd find some kind of defect in the chamber. There may be other contributing factors as well, such as work-hardening, but that damage is suspiciously consistent.

Like all reloaders, I’ll pick up brass as I can find it. I much prefer clean, new brass, matched with the packaging from the guy sighting in his deer rifle. That is opposed to decades old military brass of unknown vintage.

I will tell you that I went back to the bag of brass that I picked up that these came from and I scrapped ALL of the 7.62 x 51 brass in that bag that reflected this specific headstamp. No reason to take any chances using old brittle “free” brass.

A lot of reloaders have a pretty good handle on how many times they can use a brass case and when it's near the limit they leave them on the floor at the range. So you were probably wise to scrap that entire bag. Sad thing is that if annealed properly at regular intervals you can stretch a Lake City Case until you see it necking down above the case head. Note, if you do see necking in this area DO NOT RELOAD THAT CASE, toss it immediately. Because a case separation with the front of the case stuck in the chamber can be a giant PITA to deal with.