Firing Pin Stop modification

[CO1911Carry]

OK, OK, OK...I read through the entire 50 page sticky thread today on modifying the FPS from EGW. I did a great job in writing down what recoil and main springs to use with the mod. I wrote down I needed a #2 swiss file and some cold blue. The essential piece of info I didn't write down was the radius of the cut for a 5" Gov't!! I went back to the end of the thread a worked backward for 17 pages until my eyes started to cross, so I thought I would just ask here.

Would some kind soul please remind me what the target radius should be on the stop? Was it .050"? Thank you in advance.

[Jolly Rogers]

Read the "system" thread on this page. Tuner restates the radius. (Mine is smaller yet)
Joe

[CO1911Carry]

Thank you very much.

[1911Tuner]

Although it makes for a nice-looking stop that's correctly to original spec...there's no need to get hung up on the exact radius. I haven't cut to a specific radius in years, even after I went smaller than spec. I normally spend about 30 seconds on it. I cut across the corner evenly and make a small 45 degree bevel, and just swipe the corner on a stone until a curved surface starts to form. That's it. There have been times that I've just used the bevel.

I've seen some pictures here of some of the nicest hand-cut radusing I've ever seen, and I applaud the offorts...but I'm afraid that I'm just not as careful or as precise when it comes to that job.

[CO1911Carry]

Thank you so much for the reply. I contacted EGW about getting a pre-radiused stop based on what I read on that great but long thread and I wanted to get my numbers lined up before I ordered it. I was going to just buy the springs, file, blue, and stop at Brownells, but they didn't have the mainspring in stock. I went to Midway to buy the "kit", but they didn't have the stop. I didn't want to have to pay for shipping from each place. Since I am just going to wait until one vendor or another has all of the items I want at the same time, based on your fine description about just knocking off the corner (carefully), I'll bypass getting the part radiused at EGW since I'll have to work the sides of the stop anyway to get it to fit.

I felt embarrassed about asking about the dimension in the first place since the information was reasonably available, but I just got tired. Thank you so much for patiently responding. Just in case you wanted to know, I will be modifying my S&W PC1911 with this method.

[Hill]

I just do a nice rounded edge on it and call it good. Ive never understood the level of concern I've seen over that corner as 1911Tuner didn't say that it needed to be exactly anything, only that it be evenly cut across the edge. And if you watch what it does it's pretty plain to see that all you really ought to do is dress a sharp edge so that no defined mark develops at the impact point I have some 1/4" diamond imbedded steel hones that are 6" long and they make rounding that corner up a less than a minute deal.

Just be sure of one thing - if you are installing to an 80 series gun DON'T start with a 70 series firing pin stop. You'll be sorry if you do. The 80 series FPS, however, can be used on a 70 series pistol.

[CO1911Carry]

The concern about the radius numbers stems from just not wanting to farkle up the part. Call it fear of the unknown. Thank you for the warning about the Series 70/80 issue. My S&W is a Series 80, so I've got that clear. I just gotta relax! It's a $15 part after all. Thank you for the input.

[Hill]

If you have a 70 series FPS and want to install it to an 80 series gun you have to make the cuts in the stop to allow passage of the 80 series firing pin lock and the lever that comes up from the frame.

EGW firing pin stops are HARD steel. I have a Bridgeport mill but only had a bunch of HSS cutters small enough to do it. Three burned up cutters later I was finally able to make the thing work, but resolved then that no matter who was waiting I'd order and get the right one for the right gun next time.

The EGW firing pin stop should last forever once installed. You'll never have to give it a thought.

[CO1911Carry]

I just checked EGW and they offer the firing pin stop that will fit my Series 80 without the heavy cutting that you describe (whew). I should only have to work the sides for fit.