Ive tested Wolf, Silver Bear and GT out of my AK74, and the most accurate (keeping in mind I am inherently a poor shot) has been silver bear. But we are talking a marginal difference and Ive only shoot a few hundred rounds of each, so its a poor sample size at best. That being said, I would like to stockpile GT as its usually cheaper per round and lacquer coated for longer/better storage. I have not dont any testing to determine which of the major commercial ammunitions causes the most fauling, as I clean my rig every three weeks or so.
I actually have some Wolf and SB on hand right now, if you are up north let me know and you can see which works best for you. I have no GT to spare at the moment.
***EDIT*** Also wanted to add that the lighter grain GT is closer to 7n6 than the other two in terms of where it ends up down range (its still off a bit, but if you are sighted in with 7n6 it might make a marginal difference). If memory serves correctly, member Voron did a series of tests with commercial ammo, and found them all to be less than desirable. Maybe he will chime in as well.