New pistol was shooting about 4" left at 15 yards, unsat. Attempted drifting rear sight to the right and damn thing just wouldn't budge.

But damn it's gratifying when you finally get it done and she shoots center.  I beat on that thing with a non-marring nylon block and hammer- no luck even in a vise. I don't have a sight pusher tool that will fit this pistol.

Finally, I heated it with a torch lighter and commenced beating on that rear sight with the same punch and a bigger hammer. Needed 3 blocks of wood, a flat piece of plastic, a vise and a large C-clamp to keep everything from moving. Another set of hands would have been nice, but wasn't available.

Feels really good to fix something WITHOUT marring the finish or creating new problems.

I've removed the rear sight on a few 22/45's, yes they are tight.  Better than loose.