So I've been looking at scopes for my newly purchased Marlin 336 stainless and I think I'm pretty set on the Bushnell AK 1-4x24mm scope that has built in bullet drop compensation. Being that .30-30 and 7.62x39 are identical in regard to bullet drop, I was planning on getting that scope with a Midwest Industries 30mm mount with 1.4" off set and quick detatch. A couple questions I have are, will a picatinny rail mount to the top of the receiver with all 4 screw holes? What barrel length is tested for bullet drop on .30-30 (same as the test barrel for muzzle velocity at 24")? Will the rear iron sight interfere with the scope mounting or not?