Replacing M77/44 rear sight

[Ruger8r]

I recently acquired a very nice 3-digit which had its rear sight removed for a scope. I bought a Ruger replacement part to restore it to stock but the dovetail seems a bit over-size. I drove it partway with a light hammer and wood block but I didn't want to go hard and it sits a little high. Is it normal to have to do a shaping with a small file first?

[RoninPA]

Yes. Due to the manufacturing tolerances the sight dovetail could be a bit oversized (better it being too large than the barrel dovetail being too large). Just take your time and test it often, you want it to fit pretty snugly so it doesn't move when you shoot the rifle.