you may not need to tap the barrel. there was a scope base for traditional cva-s that used the dovetail notch for the rear sight. the base went back and shared the tang screw. cant remember who made it. i say throw a scope on. ive done it to my .58 renegade and 54 new englander barrel. you can get removable scope rings but i just use the nipple with the hose attached into a mop bucket to clean the barrel.they sell them for less than 10$ in most of the muzzy stores .