My old Ruger 77 Tang Safety 220 Swift likes The old Nosler Solid base 50 Gr bullet w/.030 freebore COL 2.727 in, 37.5 Gr IMR 4064 powder ,CCI BR-2 primers, in WW Super cases. 1/2 inch groups at 100 Yds. MV 3,840 ft/sec. I tried .015,.020,.250,and .030 freebore and found that .030 was the most accurate. I also tried H 4895,H414,IMR4831, Varget, and IMR 4064 with 55 and 50 Gr bullets , but the 50 Gr bullet with IMR 4064 is the best in my rifle. Every rifle is different but using IMR 4064 with 50 Gr bullets is a good way to start if your rifle has a 1-14 inch rifleing twist.