Re: 220 swift imr 4064 low fps
My old Ruger 77 Swift shot much tighter groups when I kept the velocity around 3600. Yes, I could get more with 55 grn bullets, but had to FL size and trim cases more often, and accuracy definately dropped when I got above the 3700 mark. I also got way way more rounds through the barrel then alot of guys did before I lost accuracy by keeping the fps down a little.
Mine had a 26" barrel, that extra 2" makes alot of difference in a caliber like the Swift.