I don't know that the quality of the pipe is the problem. When one is swinging a hammer it's almost impossible to strike the cap squarely, which is often a problem. If the damage is restricted to the upper couple inches of pipe, you could cut it off and re-thread it.
I've seen more than one set-up where people made an adapter for a jackhammer to pound the pipe down. It allows one to get a good square blow on the top of the pipe and takes away some of the labor of swinging a hammer. Even the 30 lb electric hammers pack a pretty good punch.