Check that the two prongs of the extractor are still intact and that the extractor grooves are free of mung. Check that the prongs have not peened up a burr or burrs on the chamber.
The extractor is a slide fit in it's slot in the breech block. Pretty easy to change out.
I got a Browning one from the Gunsmith Shoppe (IIRC the name) in Saskatoon. It cost me about $20, a few years back.
Cheers
Trev