I have a TGI AMD-65 with an FEG receiver, and they are parts kits, with in my case a longer muzzle brake that mimics the original.
I do not remember reading about any problems with them. I have tried many different magazines with mine and have had no problems at all. This guns has always functioned 100% with any ammo, and has been just as accurate as other ak's even with the 12.5" chrome lined barrel.
The only problems I have had with mine is the muzzle brake weld breaking. I re welded it and refinished that area and it has been good since.