ORIGINAL: G2 Shooter
Another concern of mine is rifle twist. All T/C barrels come with 1:12. Will that be acceptable for a 55 grain bullet? I have heard others say that a 50 grain is max for 1:12. Heavier bullets should use a 1:9 twist.
And vice-versa, will a barrel with a 1:9" twist cause lighter bullets to be less stable?
Any input on that?
A 1:12 twist should have no problems stablizing a 55 grain bullet. Most of the orignial rifles, commercial and military, were made with 1:14 originally, but changed to 1:12 so they would stabilize the 55 grain bullets.
I haven't had any problems shooting 40 grain V-max's with my rifle, which has a 1:9 twist. The problem here isn't stabilization, it is the thin jacket of the small varmint bullets. Leaving the barrel at 3600 fps, that means the bullet is rotating at 288,000 rpm. That puts a lot of force on that thin jacket just trying to hold the bullet together. At around the 300,000 rpm mark, the force on the jacket will become to great and the bullet will just fly apart when it leaves the barrel. Some military rifles have 1:7 twists, and they will do this. Although mine don't fly apart when they leave the barrel, they do as soon as they make contact. Not good for game animals, but deadly to a varmint.