Considering the length to size ratio of normal .577" (around 750gr.), I'd not want faster than 24" of twist. While I dearly love PacNor barrels in .17 and .20 cal.s I think a lot of their larger barrels, specifically in .50 and larger are too tightly twisted for normal bullets. If a .50 w/24" twist will shoot exceptionally well to quite long range with a 600gr. bullet, how fast a twist does a .577 need to be for a shorter vs caliber 750gr.?