[sector7g]

My Colt Series 80 intermittenly will not fire when the hammer drops (after pulling the trigger), about 1 in 50 rounds. The primer has no dent when examined.
Any ideas?

Thanks!

 

[LVMPDawg]

When is the last time you detail stripped and cleaned it? It sounds like the firing pin block isn't being pushed up all the way. If after cleaning it thoroughly you still have the problem, have a 'smith check it, maybe you need the lower arm bent or built-up.

 

[1saxman]

Pull the firing pin as part of that cleaning. Clean the pin, spring and channel. Reassemble with a light coat of FP-10 gun oil on the channel and each individual part. Chances are the fault is the firing pin block as DAWG stated, but it won't hurt to G.I. the pistol.

 

[Powderman]

Reassemble with a light coat of FP-10 gun oil on the channel and each individual part.

Unfortunately, I must disagree with part of this advice.

In my experience (26 years so far) with the 1911 series pistol, I have found the following to be true:

Lube lightly all internals EXCEPT the firing pin, pin channel, and spring. Lubrication attracts dirt that might lighten the strike of the pin on the primer.

Your other advice is spot on. I carry a Colt Enhanced Series 80 for duty. Not one failure to shoot yet--of any kind!

 

[Col. Colt]

Does your trigger have an "overtravel screw" in it? If it does (all the aftermarket "National Match" style triggers have them and Colt does install them in some models) then it is most likely the culprit.

The Series 80 is an extremely reliable system. The only two ways to induce a problem that I know of (leaving out extreme wear/ filthyness) are:

1.) It is possible to reinstall the small lever firing pin lock lever in the frame wrong - but if you do, the gun is unlikely to fire at all. Probably not your problem. I always recommend the "pencil test" after reassembly of any gun with a firing pin lock. Insert a #2 pencil into the empty, cocked gun, point it at the ceiling and pull the trigger. A 1911 should launch the pencil heartily.

2.) If the trigger cannot travel far enough back so that the firing pin lock levers are able to lift the firing pin plunger high enough out of the way of the firing pin - the gun may experience a problem exactly like you describe. Overtravel screws in triggers can cause this if incorrectly adjusted. It will be easy to tell.

Detail strip the slide and inspect the little "barbell" that is the firing pin lock plunger. if there are little "nicks" on the inside edge(s) of the "barbell", then the plunger is not completely clearing the firing pin every time. If someone has set the overtravel screw so that the trigger travel is too limited - the firing pin is still being partially blocked from free movement in it's channel. Clean throughly and reassemble. Try the pencil test, above. Found the problem? Back off the overtravel screw several turns and retest. If you are not familiar with how, do not attempt to fine tune the overtravel screw on a 1911 - you can even lock up a Series 70 (no firing pin lock) gun if you adjust it too far! Either remove the screw or get thee to an experienced 1911 smith that understands the Series 80 lockwork.

Let us know what you find. This doesn't happen often, but once in a while you will find a Colt or ParaOrd that someone has "mis-tuned" into this problem.

Warmly, Col. Colt

PS - As for lubrication, I like Tetra gun on parts where I don't want a build up that attracts lint. Rub it in throughly, then wipe it off. It allegedly gets into the pores of the metal - like Slick 50 for guns. Seems to work great. And a dab of heavy grease in the firing pin plunger's cup - where the spring goes in - will keep you from ever having to hunt for that tiny plunger spring!