Whats causing my .308 brass to crack?

alaskanman

One of my favorite rifles is an old Mossberg 800A in .308 Winchester. I got this gun used in the early 90's and used it on many hunts for moose, caribou and bears. I used to reload alot for it but now just use factory ammo. Even when I would work up loads and go to the maximum loads from Hornady, Nosler and Speer there was never any signs of presure. Just recently I noticed two cases had cracks in the neck. The first one was in a seven shot string with 180 grain Remington Cor-Lokt ammo and then today with 150 grain Remington Cor-Lokt ammo. What could be causing the cases to crack? Is the gun not safe to use? What would you guys suggest I do?

perry shooter

This seems to be a problem that shows up more and more in recent years. Most time neck cracks ARE NOT a fault of the rifle but rather the ammo . I particular the cases are not properly annealed. I would go buy some fresh ammo of another brand. I have seen ammo that looked fine when new but because of tension caused by the bullet seated in the neck the neck would develop a crack even before firing.

11b6r

Agree. In GENERAL- cracks that go AROUND the case- rifle problem. Cracks that go UP the case- ammo problem.

alaskanman

Thanks for the replies, I checked all three of my reloading manuals and the pictures they show of "case defects" of brass with cracks in the neck look just like mine. I'd hate to have retired that old gun, it isn't pretty or fancy but it sure can shoot.

Michibay

Might want to somehow report it to Remington...Maybe try Winchester or Federal...or try finding some older stock of .308 that someone might have around. Years ago, I had trouble with my Savage 99 in .308 using NORMA ammo. I think it was too hot...the cases would expand and I had trouble ejecting them...but what do I know

alaskanman

I tried a box of Federal High Energy loads 5 or 6 years ago and they worked fine. I had no problems with Federal Classic ammo, might've just been a "bad" batch of Remingtons. Thanks for your replies.

gunsmith12345

The chamber may be bounded out of spec by now. A head space gauge may not indicate issues with chamber neck dimesnions. I would brush the inside of chamber and neck area, remove oil and possible deposits. Then get some new Remington heavy weight factory loads, exapine the spent brass for cracks and gas leaks. The case is just a big high pressure gasket...look for small black marks on the outside of case - indicates cracks. If you see these, the chamber may be extruded off dimensions at the neck, which is the high pressure area for the 308. If so, you love betesy but retire her. Reloading tools also ware out. As the others have advised, the brass wares out too, especially 308 due to the high pressures.

alaskanman

Wow, thanks gunsmith12345, that's some detailed information. I'll try that this weekend. Would having a gunsmith change out the barrel be a solution?

Sage28

As a rule head space has little to do with neck cracks,the necks need to be annealed,as reworking the brass,the neck expander has
made the necks thinner.I had this happen 2 weeks ago. Suggest you
pull up, Varmit Al`s Reloading Page. A great full article on all the
phases of reloading.Hope this helps.

PredatorSniper

bad ammo

RCrosby

Just putting my ignorance on display for y'all this morning,
but how does a chamber get "extruded off dimension at the neck"?[:D]