Highly recommended for both heavy recoiling 1911s and also 1911s with shorter than 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 we typically shoot for the middle of that range, 46-48 Rc. The Extreme Service FPS is made .482" wide so it can be fitted to your slide and extractor to prevent extractor "clocking". It has chamfered fitting pads on each side to make your job easier and the FPS fit better into the slide.
It has a 3/64" radius machined on the bottom rear corner and a 3 degree angle at the top rear face, both of which act to take away mechanical advantage from the slide when it's cocking the hammer, by moving the contact point to the bottom of the hammer face. This will retard the initial movement of the slide, slowing it's rearward speed a little. This will allow short length 1911s to have less imbalance between the slide's speed and the magazine spring's force on the last couple of rounds, reducing the bolt over base type of malfunctions caused by the slide outrunning the magazine spring. Users report that it also softens the felt recoil even on full size 1911s.
This firing pin stop is configured for Series '80, all calibers of Commander and smaller models, plus all mid-caliber Gov't models. If your frame and ejector look like the picture above, this is your firing pin stop.
The things that make a Harrison Design firing pin stop better -
1) H-D fps are made in all varieties and materials possible on a 1911 so you don’t have to make extra machine cuts to get a real Commander S-70 configuration, for example. Or a .45 Gov’t S-80 that matches up fully to the end of the disco rail for another.
2) The topmost radius is left at USGI dims instead of just running them out into the extra wide side flats. This results in less shaping of the top radius to get the fps to seat all the way up into the slot.
3) The sides are made as fitting pads and the back edge has a nice chamfer to make it easier to fit to the slot and the extractor.
4) The sides are made to the correct thickness so they will go into the extractor slot without extra filing.
5) The bottom hammer-cocking radius and a 3 degree top angle are already cut.