I have different scopes on all3 barrels. A 4 power Nikon on the shotgun, 3x9x40 BDC Omega Nikon on the 50 cal BP and a 3x9x40 Nikon BDC Buckmaster. Once you zero them in, you don't want to take scopes off the barrel unless it is really needed. You can remove the barrel and scope, as one piece, to replace with anotherscope and barrel, and not be worried about being zeroed in.