I have the same AR from Windham,even thought I have less then 1000 rounds through it I like it so much I added the SRC in .556 about 2 months ago to my collection,now with the weather turning warmer and the snow is just about gone I'll get both out more and see how they both do with a few thousand more rounds sent down range.
I took my new Windham Weaponry 7.62x39 SRC to a local indoor range today and fired 110rds of Wolf 123gr FMJ lead core copper jacketed (no steel in the bullet) ammunition. There were three failures to fire the cartridge. Each time the cartridge fired the second time. Ejection was 100%. The D&H magazine (factory) ran 100% as did the Ross and Zhang magazine. The D&H magazine was a pain to load once I got to 20rds (of 30rds) and the Ross and Zhang magazine was easy to load the whole way. The USA 20rd magazine literally wouldn't feed the first cartridge. I'll give the chamber a good cleaning and take it back again to see if I have any failures to fire. Of course I won't be using the USA magazine.
You'll want the enhanced firing pin (longer, or you can modify a standard AR15 pin pretty easy) and Wolf gunsprings extra power hammer spring.
When I was playing this game I had no ignition problems after using these two items.
I sent you a PM.
I called Windham and spoke with a guy in their customer service department. He said that their 7.62x39 AR15's come with enhanced firing pins. I asked about the extra power hammer spring and he said that he wouldn't suggest going that route unless I've eliminated the ammo coating and/or a dirty chamber as the cause of the problem. The failures to fire only happened with the first two magazines through. The last two all fired 100%.