How small groups do you need? We shoot a winter bullseye league. I'm not a bullseye shooter but we have had this discussion and I've shot groups (rested) with different ammo in several of their 41's. We shoot the 50 ft cof and virtually any of the bulk ammo will keep 10 rds clustered inside the 10 ring on the slow fire target. The differences between the usual standard, CCI standard velocity, and the more expensive stuff vs Fed or Win bulk ammo, at least at 50 ft, was at most very small.
There seemed to be more to be gained by having ammo the gun runs reliabley so you're not shooting alibi strings.