This is your firing pin stop if you have a 9x19 caliber 1911, expecially those with Gov't Model slides. The Extreme service firing pin stop is CNC machined out of an oil-quenching tool steel that was chosen for a balance of impact and wear resistance. GI hardness is 44-50 and Harrison Design shoots for 46-48 Rc.

The Extreme Service FPS is made .480"" wide so it can be fitted to your slide and extractor to prevent extractor ""clocking"". It has a chamfered fitting pads on each side to make your job easier and the FPS fit better in to the slide.

It has a maximum sized radius machined on the bottom rear corner to make it easier for the 9mm cartridge to open the slide. It will reduce the sluggish cycling that many 9mm 1911s have. The firing pin stop is configured for the Series 70, 9mm Governmet model plus the Commander and smaller models.