So a 1-12 or 1-14 will work just fine for me with 55gr rounds (or more)? And a 1:9 will work will 55gr. BUT I can't ever really use heavier bullets effectivly?
Other way around. 1-12 and 1-14 will work up to around 60 gr. 1-9 will work with up to 69 or 70 gr. Heavier (usually longer, which is what really counts when discussing twist rates) bullets will require a faster (also called tighter) twist, 1-8 or 1-7. These twist rates and bullet weights are for 22 centerfires, by the way. Different bullet diameters will require different twists for different bullet weights. Velocity can compensate somewhat for twist, but not much. - dan