Full auto 1911 . . . ?

[tangolima]

This is called slide surge. It won't cause doubling or full auto, as the half cock notch will catch the hammer.

The bullseye reload won't prevent a worn sear from doubling. It is probably a bad habit for pistols other than ultra competitive bullseye shooters.

There is a series of checks for proper sear engagement. A competent pistolsmith will go through them after his work to make sure the pistol works correctly before returning it to his client. Full auto due to worn sear won't happen total out of blue. It is usually preceded by doubles, whose frequency increases if the shooter ignore the warning and keeps firing.

-TL

 

[Mike_Fontenot]

This is called slide surge. It won't cause doubling or full auto, as the half cock notch will catch the hammer.

Sometimes the hammer gets caught by the half-cock notch, and sometimes it doesn't: the inertial trigger pull CAN keep the sear away from the hammer until the hammer is past the half-cock notch. When that happens, you get a round fired, and the ensuing slide cycle(s) can cause one or more repeats of that. People who don't mind 4-5 lb triggers or more don't have to worry about it, but light-trigger lovers DO. And not all light-trigger lovers are strictly bulls eye shooters, in spite of the conventional wisdom.

 

[RickB]

The original grip safety design incorporates a trigger overtravel stop. At least one modern maker of beavertail grip safeties has redesigned the internal configuration to allow removal of the grip safety without first having to remove the mainspring housing. In the process, the built-in trigger overtravel stop was deleted, which means you are relying on the (moveable) trigger overtravel screw.
If the overtravel screw migrates outward, allowing excess trigger travel, the trigger will push the sear spring off the disconnector allowing the disconnector to "float". I think it's actually more like "bump fire" than full auto, but there's certainly a sense of the gun "running away".
I've witnessed 1911s doubling due to hammer, sear, and/or disconnector wear, and sometimes it can be fixed, at least temporarily, by tweaking in some additional sear spring tension.

 

[T. O'Heir]

"....that would make it jump to full auto?..." Lots of stuff. Busted sear. Busted firing pin. Very lightly loaded ammo. Highly unlikely for an issue pistol to just go FA though.
Mind you, the Ordnance guys tried to make an SMG out of a 1911 just after W.W. I. Or near then. Didn't work well.

 

[happyguy]

Dillinger had a full auto 1911. Modified by an Arizona gunsmith back before the NFA of 1934 when anyone could have one.

If memory serves it is on display at the FBI museum.

Googled it. Complete with compensated barrel.

http://www.gundigest.com/article/a-full-auto-colt-1911-only-if-your-name-is-dillinger

I wonder what that gun would fetch at auction with all that history.

 

[James K]

Several makers, including Colt, have made experimental models of 1911 type pistols with a full auto capability. Some, like the Star were marketed commercially.

Unintentional full auto fire is usually the result of a worn or altered sear so that the stopping of the slide as it goes into battery jars the pistol enough that the sear disengages and the hammer falls. Normally, the sear would re-engage in the half cock notch, but "normal" doesn't always apply to DIY trigger jobs.

Years ago, a local "gunsmith" specialized in 1911 trigger jobs. But he go the pull so light that the hammer kept dropping into the half cock notch when the first round was chambered, damaging his perfect sears. He solved the problem by grinding of the half-cock notch with the predicable result that some of his guns went full auto. After some discussions with the cops and a lawyer over that and other issues, including lack of an FFL, he chose to take up lawnmower repair. AFAIK, none of the mowers he worked on went full auto.

Jim

 

[Mike_Fontenot]

Unintentional full auto fire is usually the result of a worn or altered sear so that the stopping of the slide as it goes into battery jars the pistol enough that the sear disengages and the hammer falls.

OR, alternatively, that the trigger/disconnector leaf of the sear spring has been set so light that the trigger moves aft due to its inertia when the slide slams home. If the trigger is still holding the sear away from the hammer as it passes the half-cock notch, the hammer will continue on to the firing pin, and the gun will fire. But inertial trigger pull won't happen unless the trigger is released and reset before the slide slams home. This normally is the case when the first round of a new mag is slingshotted into the chamber (without pulling the trigger first, which is called a "bulls eye reload"). It CAN also happen after firing a round, if you slap the trigger instead of pulling it all the way aft and holding it there until after the slide has slammed home.

 

[polyphemus]

Somebody please put this thread out of its misery.

 

[Ozzieman]

I have a mid 70's gold cup that has fired multiple shots. It has a light trigger and if you cushion the trigger it has gone auto for up to 3 rounds.
The strange thing, I am unable to do it. Several others friends it has.

 

[Mike_Fontenot]

It has a light trigger and if you cushion the trigger it has gone auto for up to 3 rounds.

What do you mean by "cushion the trigger"?

 

[Ozzieman]

You don't pull through with the trigger, when it goes off the recoil resets the sear as the slide goes back and when the slide slams home the gun will go off again as the gun moves forward in your hand.

 

[Mike_Fontenot]

You don't pull through with the trigger, when it goes off the recoil resets the sear as the slide goes back and when the slide slams home the gun will go off again as the gun moves forward in your hand.

OK ... same situation that I was referring to as "slapping" the trigger ... kind of like the way you use your finger to test for a hot stove. Some shooters intentionally do that, as a way to be able to shoot followup shots faster. But it IS incompatible with a very light trigger.