View Full Version : 1911 Firing pin stop
April 28, 1999, 11:44 PM
Firing a new 1911 pistol last week, I had a (seeming) jam. After a tap and rack, a buddy noticed a piece fall out of the pistol. It was the firing pin stop.
I ended up needing to repair the pistol at home, since I couldn't fix things at the range. The firing pin was quite difficult to get back through the hole in the breech of the slide. Once I did, the gun reassembled and seemed to cycle normally.
Any ideas? I was wondering if the pistol had a burr in the firing pin channel that retained the firing pin in the forward position. Then when the slide recoiled back, the firing pin stop could just fall out. If that is the case, it is fortunate that the gun didn't go full auto?
In any case, the pistol gets shipped back next week. It wasn't cheap and I expect a more reliable firearm!
Any ideas on what happened?
April 29, 1999, 08:02 AM
Hawkeye, while this isn't an everyday occurance, I have seen it happen several times. Production firing pin stops are a tad undersize for the channel that they sit it in being made this way for easy assembly/disassembly. 99 times out of 100 the force exerted by the extractor is enough to keep them in place. Sometimes however it isn't. Several competition shooter install a set screw in the stop and one of the more popular mods to the 1911 is to have an oversize stop fitted snugly to the pistol. Either way works. I wouldn't expect to find anything wrong with the firing pin but it never hurts to be sure. If you decide to keep the gun, the next time you take it to the range, shoot your first few stages with only two rounds in the pistol. Just this past week end my son's 1911 began a "failure to fire" series of malfunctions. On inspection the back of his firing pin had peaned out to fill the hole in the slide stop and refused to be budged by the hammer. A replacement pin was all it took. At around $6 this might be cheap insurance for your pistol as well. George
April 29, 1999, 10:57 AM
Good morning, George and Hawkeye,
I agree that the firing pin stop falling out is rare, and the fix ideas are all correct. But I wonder if something else may be wrong with that pistol. In normal firing, the firing pin should stop in the primer before its back end goes in far enough to clear the firing pin stop. Maybe a good idea to check headspace, cartridge case length, firing pin length, also.
April 29, 1999, 12:27 PM
FWIW, I had a Colt Series 70 Combat Government Model whose firing pin stop dropped partially out of position at the range. The gun jammed when, if I remember correctly, the firing pin stop caught on the hammer tang as the slide moved forward. I was shooting factory ammunition.
On later inspection the stop seemed a little loose, but a lot of them do. The firing pin looked okay. However, I never did find out the exact cause of the problem, because I returned the pistol to my dealer for a refund rather than hassle with a repair. It was a used gun when I bought it, and, although it seemed to be in good condition and not fired a lot, it could have been tinkered with or, of course, defective to begin with.
April 29, 1999, 03:13 PM
With gun parts manufacture being a cottage industry in the world, and even top line manufacturers becoming more careless, this kind of thing is going to be very common.
I was only partially kidding when I once wrote, "If it doesn't say 'U.S. Army, Model 1911A1", it's no damn good."
April 29, 1999, 06:04 PM
I didn't think that a firing pin could be driven forward far enough to let the retainer fall out, obviously I was wrong. I'd try two things - first a heavy duty firing pin spring, second an oversized retainer that has to be fitted to your slide. I've got 4 1911's, none have a retainer loose enough to fall out on it's own.
April 29, 1999, 09:13 PM
Thank you gentleman. I appreciate your experience and advice.
I'm going to return the pistol tomorrow and see what the gunsmith wants to do. I was surprised, since I've fired 1911's for a while and never had this happen.
I appreciate the self-repair ideas, but I reckon I owe it to the smith and myself to give him a chance to make things right. I won't get seriously hacked unless this visit doesn't get things working smoothly.
April 30, 1999, 10:45 AM
I have done some research, and like almost everything else about guns, the situation is a little more complicated than it seems.
When the M1911/A1 is fired, the hammer drops on the firing pin, driving it forward. It should not go far enough forward at that time to free the firing pin stop. You are right, Motorep.
But that is not the end of the story. When the cartridge fires and the bullet starts to move, the slide moves back in a hurry. It moves so fast that it does not push the hammer back like we think. It hits the hammer a hard blow, and kicks it downward, where it bounces off the grip safety.
At this point, the cartridge has been partially extracted, and is forward against the hook of the extractor. The firing pin is still forward and is being pushed farther forward in relation to the gun by its own inertia (especially if the firing pin spring is weak), the hammer is not touching the slide or the firing pin stop, and the recoil has moved the gun.
The firing pin stop is free to move, but it really is trying to stay in one place while the whole gun moves in recoil. The result is that it jumps out of its position in the slide. This will cause the gun to jam and the stop usually falls out while attempting to clear the jam.
You can see that the whole thing depends on a lot of involved timing, which is why dropping the firing pin stop doesn't happen often. All the solutions given are very practical.
Taking the gun back to be worked on won't guarantee a fix unless the gunsmith makes some of the changes already suggested.
P.S. For those who doubt that the hammer is knocked back hard by the slide, look at the underside of the firing pin tunnel in the slide. If the gun has been fired much, there is a dent, caused by the hammer bouncing off the grip safety and hitting the slide as the slide recoils.
April 30, 1999, 01:06 PM
JK--in reference to your postscript, you just solved a mystery for me. I have an old BHP with just such a dent underneath the slide. Until now, I couldn't figure out where that dent came from.
April 30, 1999, 03:57 PM
You are welcome, Jimmy. Just a little fact not many people know.
Another one. The reason the M1911/A1 firing pin stop is not made tighter is that the pistol was designed to be detail stripped with only the fingers and parts from the gun itself. If the mainspring housing pin can't be punched out with the safety, the safety can be used to remove the firing pin so it can be used as a drift punch to remove the housing pin (the slide is the hammer). It or the hammer strut are used to remove the other pins and the safety and slide stop plungers and spring. The third leaf of the sear spring is used to disassemble the magazine catch. It's simple.
P.S. to Jimmy - on your HP, the end of the slide stop pin is smaller than the rest. That makes it easier to get in, but see if it fits into the firing pin stop just right to remove the stop and firing pin.
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