Al, glad to see you made it over here.
I'm looking forward to the Performance Rifle course also. It's going to be awesome!
I would echo the sentiments of Bidah. I've used plenty of Wolf ammo and never had any functional problems with it, so long as your using the gray, polymer coated stuff. The velocity is off a bit, it burns dirty, and it's not the most accurate stuff around, but for volume practice inside 100 yards, I think it's good stuff.
You may have to lube up the AR a bit more or increase your cleaning schedule, but otherwise it should work fine. I wouldn't hesistate to use it.
Ever find out what was wrong with your M4?
Erik