I have a 20 gauge Pardner barrel that I bought last year off the classifieds and I had also bought a scope rail, and finally last week I took it to the gunsmith to have it drilled and taped.
Well, they wanted as much to drill and tap it as a new gun would cost so I brought it home and decided to do it myself. I took it slow and checked and double checked before I drilled one hole and the finished product came out fine, and didn't cost me a thing. I drilled and taped and also epoxied the base and mounted a 4 X 32 shotgun scope I had and it shoots Remington sluggers into a nice 2" group at 50 yards.
This should make a great all around gun for deer, hogs, using slugs, and birds if I want to load up with some shot shells.
I also have a 20 gauge Tracker ll that came with a scope rail mounted, no iron sights, and I have a Simmons 3 x 9 mounted on it, and it shoots Remington Buckhammers like a precision deer rifle. I've taken a couple deer and numerous hogs with that gun.