Most 1911 shooters realize the importance of a properly fit and tuned extractor, but it is my impression that plenty do not appreciate the need for an equally well fit Firing Pin Stop.
The Firing Pin Stop’s name gives away its main purpose, keeping the firing pin and spring inside the slide where it belongs. The next purpose of the stop is its role in properly positioning the extractor and holding it in place during firing.
You can have the greatest extractor ever made, dressed and tuned by John Moses Browning himself, and if the extractor is loosely retained by a drop-in FPS, the extraction and ejection will be erratic.
Considering that the 1911 is a Controlled Round Feed design, the extractor is heavily involved in both the feeding and emptying of each round.
An over-sized firing pin stop is fit by dressing down the sides until it barely slides into place in the rear of the slide. The extractor will be locked into place and the consistency of feeding, extraction and ejection will be greatly improved.
EGW, Harrison and Wilson Combat are 3 brands that I have used. I prefer the Harrison stop over all others. I’ll go as far as saying no other sub 25 dollar part will do more to improve the functionality of your 1911 pistol.