If Ii can afford it, I buy WWB, but usually all I can afford is wolf. When my dad bought our sp1 in the early 80's he ran norinco through it, up until the late 90's. Since then its had its share of wolf, s&b, winchester, and a bit of various milsurp all without problems related to the ammo itself. Local shop sells wolf for $2.88/20, and next cheapest is the new polymer cased stuff(which is very nice,my ar loved it) at $4.89/20. If I was looking for accuracy I would only buy the high quality, but since all I really do is plink wolf is just fine for me. My ar's had steel case run through it most of its life without any problems, and I see no reason at all to change.