I was testing some CCI Standard Vel. in my son's Savage Mark II heavy barrel, and took the 581 along just for kicks. Bottom line is, 581 shot 3/8" groups at 50 yards with the stuff. (With a 4x scomp and my old eyes, anything less would be mostly accidental. Never shot much other than Rem. Hi. Vel. and it grouped around inch most of the time. Guess it is time to test some more ammo before spending big bucks on a gun that shoots like that already.