Very good ... but not exactly drop-in
To be sure, this is a quality part ... but it's not exactly "drop in" (at least not on my Buck Mark). The extractor hook was a bit oversize, preventing the cartridge rim from sliding up into the bolt face. Stoning the extractor to fit and adding a slight entrance angle to the cartridge engagement surface (to help with feeding) is not difficult ... not really different than typically what needs to be done with any extractor. Very little material needs to be removed. And while you're at it, you might as well order a new extractor spring (Brownells no. 149-200-456WB). If the old extractor is worn out, the spring is likely done as well.

