221 Fireball - what twist rate?
My search for a .22 caliber centerfire barrel for my Encore pistol has caused me to research several promising cartridges. First was the 5.7x28mm, which I decided against due to a lack of brass availability. Second, the 22 Hornet, rejected due to its thin brass. Finally, I looked at the 223 Remington, which (and this will sound silly) is a bit too much gun for what I want. Now, I've settled on a 221 Remington Fireball barrel. I've decided on an MGM 12" blued heavy taper barrel, but I'm unsure of what twist rate I need. I'd like to be able to fire 55 grain FMJ bullets as cheap target fodder, along with similarly weighted V-Max and A-Max bullets for more precise shooting.
What twist rate should I go with, and what would be the upper range of bullet weights that twist could handle at Fireball velocities?