New upper on Double Star Lower.  I took Brown Bear and Golden Tiger to try.  Had two Stoner 5 round mags and 2 Bushmaster 30 rounders.  It ate the Brown Bear without a hiccup and did 2.5 MOA at 100.  The Golden Tiger did better accuracy wise but short cycled every few rounds.  The Stoner mags ran without a hitch with Brown Bear, but the Bushmaster would refuse to chamber if I put in more than 6 rounds.  All in all, I like the upper and it's fun to shoot.  Too bad about the Golden Tiger.

My Armalite 7.62x39 short cycled some with Wolf during the first few dozen rounds, but after a few dozen more the short cycling disappeared.  Might be that your gun just needs a little break in.

Need pictures!

What kind of upper did you get?

Sounds like pretty good performance!

Bushmaster upper, I'm at work now (Shhhhhh) so pics will have to wait.

Run some yugoslav m67 through it and see how your groups are with that.

That would mean I would have to clean it !  I only clean my AR's every 5 to 600 rounds.