When I first got it I put about 200 rounds through it. About every second or third round wound not load. Some time the bolt would catch the lip of the round, some times the bolt would close on an empty chamber sometimes the round got pushed just above the chamber. Usually the last 10 to 15 rounds in a mag would run. I assume because there was less pressure on the bolt.
I took it home and cleaned the gas system until there was no carbon coming out at all. Took it back to the range yesterday, same thing but it was more like every fifth round and when the gun got hot it ran perfectly.
There is a Smith were I got the gun from. Should I have him fix it or is there an easy fix for it.

Also I used six mags and two drums. I used two types of Tula and Wolf (three types total but not mixed up.) This is a 7.62x39 gun.

Yesterday it was almost exclusively Tula FMJ and I went though about 300 rounds.
I should also mention this gun was a 308 that's now been converted to 7.62x39 by Hard Times Armory pre-86. I have spoken with two other individuals that have the same conversion guns that run 100%.

Try a different recoil spring.

It may be under-gassed though. May need larger gas port on barrel.

The recoil spring does appear longer than most. I'm sure I have one on another gun that's a little shorter. I'll give that a try.

It may be the original one.

My saiga 308 spring is different than a 7.64x39 spring.

So after a few more times at the range if found it runs great when it's clean, and acts under gassed when it was not cleaned between uses. Anyone ever see this in an AK before?