Q: I want to have my Winchester Model 70 rebarreled to something faster than the .22-250. The .220 Weatherby Rocket and the .22- 250 Ackley Improved passed through my mind and kept right on going. Then my gunsmith suggested the .22-284 which is rare enough to tempt me to try it. What are your thoughts about this?
A: The .220 Swift moves a 50gn bullet at over 4000 fps, and Weatherby’s improved version, the Rocket, added about 200 fps to that velocity without increasing the pressure. Today the Rocket is obsolete, but a faster .22 is found in the .22-284 which shoots the 50gn bullet at 4400fps at no greater pressure than the .220 Swift produces. Personally, I think the .22-284 is at its best with heavy bullets weighing from 70 to 90 grains in a barrel with a 1:8″ twist. It would make a pretty fair deer rifle with a load pushing the stout RWS 74gn Cone-Point at 3700fps or more. I’ve never worked with this wild and wooly wildcat so don’t ask me for load data. Maybe you could start by using data for the .224-6mm Improved?