AR 15 in 7.62x39

Mobuck

I just aquired an upper supposedly made by Colt in 7.62x39 but can't find any markings on it. It looks almost new, fired just enough to dirty the barrel. I shot a few rounds to see how it worked but had a couple of firing pin strikes that failed to fire the first attempt. Both fired second try. This is some 6-7 year old Russian ammo and I have only used it in SKS/AK rifles up to now with no problems. Are there similar problems with this setup or just the one I got? I have some reloads that I made up for a Rossi single shot but I hesitate to run them through the magazine since they aren't crimped. Anyone else have suggestions.

4440rk

That AR might not have quite heavy enough hammer strike for that Russian primer. I have a 7.62X39 but only shoot US ammo with .308 bullets. Cause that is the way the barrel is made. The Wolf and etc has .311.
So I kinda figure .311-.308=.003 to large a bullet. IMO and my rifle. But I don't know about that Colt barrel and its bore.

sharpshooter039

I know for a fact the handi-rifle does not like russian surplus,I own 2,you will have to hit several of them twice for them to fire,the primers are too hard,I would guess thats the same problem you are having

jonk

Just as a general thought, a .311 bullet squeezed down a .308 bore probably won't raise pressure enough to cause a dangerous situation, but will certainly effect accuracy negatively and possibly lead to quicker throat erosion. But I also wouldn't assume it is a .308 bore unless I had personally slugged or at least checked it with a set of calipers.

Sounds like some handloads with commercial primers are in order.

Mobuck

With only 4 rounds fired the accuracy was great with the Russian ammo. As soon as I get a proper sized expander ball for my die set I'll try some loads with 125 Ballistic Tips. My Lyman die expander is way too big for good neck tension even when using the 308 ball with 311 bullets.