from research, it seems as though most people have better luck with 50 grain than 55 grain out of the swift. I just bought some 50 grain bullets to try to work up a load in the spring for the 220 swift. Right now I have several hundred rounds of swift loaded with IMR 4064 and 55 grain ballistic tips, but they are like a 1" grouping. My .22-250's love the 55 and it seems like more people have success with 50s out of the swift. Give some things a try.