The sights are not offset just that when you bore sight the bore points slightly right of the target while the sights are center.

Maybe to simplifly my question leaving out the cast bullet factor. Would a full power military rd shoot the same in a left hand twist bbl 31-1/2" as it would in a 17.8" barrel at 50 yrds if the sights and the bore of each were aligned to center aim, or would the shorter barrel cause the bullet to impact to the left of center? There must be a reason the sights on the carbine were made to have the bore point to the right of the sight. The only thing I can think of is that the longer and the shorter barrels do not shoot to the same point of aim with the same bullet, Ray.