Are you talking about hunting at long range, or long range target shooting?
Mechanincally a good 44 mag can be expected to produce 2 moa accuracy. If you really want to know what a good sixgun can do, work up loads from a solid rest off the bench and then practice at extended ranges.
While I personally don't care for how a scoped sixgun looks nor do I have any desire to pack one, I do know that I've always been able to shoot much better groups with a scoped sixgun than an iron sighted sixgun. Having the magnification to give you feedback on how unsteady your grip is and the added weight to settle the gun and absorb some of the recoil will more often than not improve your ability to hit at extended ranges.
