I generally shoot the JSB 18.13gr through my M3 Impact. I have it tuned to shoot them around 915fps, but last order from pyramid I bought some JTS in a couple weights to try out. first up was the JST 22.07gr without changing the tune shot them amazingly well at just over 800fps (probably 1/2 inch groups) Then I tried the JST 18.1gr and there were a few flyers untill I turned the hammer wheel back from 16 to 12 and bam! one hole groups at 60 yards. I like the 22.07gr, pretty good in the breeze today.