308 cal primer pocket expanition

[roundrockcrawler]

Does anyone else have this problem, when I build reloads for my DPMS LR-308 the most I can get is 4 times reloading the same brass before the primer pocket swells to where the pocket is to loose to hold the primer. This is starting out with Winchester new brass first, also I'm not using an excessively hot charge either 44.3 grains of Varget with Win LR primers. My bolt gun in the 308 cal I can easly get 8 or more reloads out of same brass then the necks start spliting, but no primer pocket swelling, what your oppinion on this delima.... Thanks

 

[hessian]

Re: 308 cal primer pocket expanition

I dunno. However,my book says that 43.2 gr. is a max load for 155gr. bullets and that42.7 gr. is max for 168. These are gas gun loads specifically. Not bolt gun loads. You are way over. Get a book.

 

[zuke]

Re: 308 cal primer pocket expanition

Try different brass

 

[1lnbrdg]

Re: 308 cal primer pocket expanition

44.3 is not a hot load in my rifle but if you are trashing primer pockets in 4 firings, it sounds like it's a hot load in your rifle.

 

[l115a3]

Re: 308 cal primer pocket expanition

It should be lot#

 

[judgedelta]

Re: 308 cal primer pocket expanition

What in the world is an expanition? Does anyone have an explanation?

 

[FLIGHT762]

Re: 308 cal primer pocket expanition

308 AR gas guns can beat the brass. You need to lower your powder charges. I have a old, first production SR-25 that will stretch primer pockets out on the first firing using the same loads I use for my bolt guns. I have to drop powder charges 2-3 grains less to get at least a couple of loads out of the brass.

 

[gunsnjeeps]

Re: 308 cal primer pocket expanition

Looser chamber, brass not supported through pressure curve. M1A/M14 gets 5 reloads before pitching the brass.
Not knowing what bullet your loading I won't guess if your at or above a max load but primer pockets growing is a good indication of it.

What bullet?

 

[stranded]

Re: 308 cal primer pocket expanition

OP, There is a thread in semi auto section (why are AR10's hard to shoot). Someone talks of over-gassing causing primer pockets to swell. Maybe an adj. gas block could help?

 

[CanSniper]

Re: 308 cal primer pocket expanition

What bullet?

 

[roundrockcrawler]

Re: 308 cal primer pocket expanition

Sorry I took so long getting back been out of town, the bullet I'v been shooting is 168g SMKBT and 178g SMKBT with Win LR primers 2.80 oal, trimmed brass 2.15 .Started out at with 42 grains of Varget from the book, worked up from there to 44.5 but settled on the 44.3 g after 44.5 g started poking holes in the primers and groups were no better. I experinced no excessive brass stretch or neck failure or burn off powder residue around primer pockets. Since no normal signs of high pressure, that I could see or understand, and also I'v been shooting this same load in the heat all summer long in Texas, with the only problem being, primer pocket swelling. Thanks for the good info,I will read up on the over gassing as Stranded suggested and consider lowering the charge hopefully I won't lose any of the accuracy.. Thx