without being able to look over the gun, i probably guess that his gas system or extractor would be the issue. he may not be getting enough gas back from the Wolf to fully eject the rounds, or his extractor spring could need some beefing up (check out bravo company for extractor upgrades). another area to look at is proper lubing in his gun, specially in and around the BCG.
i haven't had any problems with wolf in any of my AR's. and to be totally honest, i want to know that they will run on just about anything i feed them, specially if that is the piece that you are staking your life or your loved ones lives on.