The Myth of Firing Out of Battery et al

1911 recoil

The Myth of Firing Out of Battery

We occasionally hear about somebody blowing up a 1911…usually with reloads, and usually loaded on a progressive press…but sometimes on a single-stage press. Of course, nobody wants to believe that this event was caused by a double charge…because nobody wants to admit that they made a mistake or that their double-throwdown progressive loader had a hitch in the gitalong.

Let’s assume that there’s nothing mechanically wrong with the gun, such as grossly excessive headspace or lost head support due to Dremel Dan’s most excellent ramp’n’throat job. (More on that later)

The usual theory is that the gun fired out of battery. I hear that one a lot, and I’ve come under hostile fire for pointing out that pulling the trigger can’t fire the gun far enough out of battery to blow it up. Can’t happen. It’s mechanically impossible.

But, the flak starts flyin’ and they demand an explanation…often accompanied by much snark and condescension…so here it is.

John Browning…master of redundancy and with a penchant for designing multiple functions into one part…saw to it.

Let me repeat that. The pistol can not fire be fired by pulling the trigger when it’s far enough out of battery to blow up, and it has nothing to do with the disconnect. That’s not the disconnect’s function anyway.

A quick description on the function of the locked breech, short recoil operated pistol.

At nominally .100 inch of slide travel, the bullet exits. At .010 inch more travel, the link just starts to tug on the barrel. The upper lugs are still vertically engaged with the slide’s lugs…and the barrel and slide are still horizontally locked together. Slide and barrel can’t separate, and the breech can’t open.

At .110 inch out of battery, the face of the hammer can’t touch the firing pin. The hammer stem impacts the bottom of the firing pin stop…and if the firing pin stop has the original spec 5/64ths radius…it loses the ability to hit the firing pin at around .090-.095 inch out of battery.

And even if it could hit the firing pin at .100 inch out…the slide still has an additional .100 inch to move before the upper lugs are completely disengaged. The bullet will be gone by that point, and the breech can safely open.

So, the next time somebody tries to tell you that the gun fired out of battery…explain it to’em…but expect some flak.

Yeah. Ask me how I know.

A word on the disconnect:

I hear another myth repeated from time to time on filing the top of the disconnect flush with the top of the frame to create a poor man’s machine pistol. I even knew a couple guys who tried it and wound up with single-shot 1911 pistols that required manually cocking the hammer in order to fire another round. They pretended that they didn’t know why their pistols had suddenly stopped working, but only one admitted to it after I pressed him. The other one stuck to his story.

I replaced their disconnects and sent’em on their way after explaining what had happened and a semi-stern lecture on federal laws concerning intent to manufacture a machine gun. Whether it actually worked or not is irrelevant.

All their efforts accomplished was to cause the hammer to ride the slide down, and that’s not enough to bust a cap. or those who can detail strip a 1911, assemble it without the sear and disconnect…then manually cycle the slide slowly and watch the hammer. You’ll notice that the center rail of the slide supports it almost all the way down, only releasing it in the final .025 or .030 inch…and the hammer just isn’t moving fast enough to drive the firing pin into a primer with enough momentum and energy to light it. Unless the firing pin spring is exceptionally weak, I doubt if the pin will reach the primer at all.

Function of the disconnect:

The trigger never touches the sear. There’s a gap between the trigger stirrup and the sear that the disconnect bridges so that when the trigger bears against the disconnect…the disconnect rotates the sear and releases the hammer. Then, when the slide moves backward and pushes the disconnect down into the disconnected position, the gap reappears and lets the sear reset into the hammer so that the hammer’s full cock hooks can grab the sear and ready the gun for the next shot.

And…The hammer doesn’t go directly onto the sear until the hammer has moved forward far enough to release it and let it fall back onto the sear. This function is necessary to protect the sear crown and the hammer hooks from impact damage because the hammer isn’t cocked smoothly. It’s slammed backward and bounces off the grip safety tang. If it fell directly to the sear, the sear and hammer hooks would be quickly destroyed.

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5 Responses to The Myth of Firing Out of Battery et al

  1. sean December 24, 2014 at 11:56 pm #

    Not fire…right wont fire on 1911’s..now. .with out the aid of high speed cameras. ..a glock 20 in 10mm with factory recoil spring and barrel and a true 80’s type load has been seen to fire normally and during the pressure spike the guide rod spring allows the slide to back out a fraction of inch…allowing the smileys you read about..not bulge! Bulges are defined as all the way around the case..belly or smile. .sure looks to match the feed ramp area and a case slightly out of battery..a 22lb for mid power..24lb some high powered 10mm…has fixed many problems like this and feeding issues when norma level rounds are used..an aftermarket barrel is best…but all 10mm glock users should get a stainless 22lb gsa..thank you sir..waiting for a slim glock 15rd long slide to come out. ..10mm is the #1 semi auto combat handgun..

    • John Travis December 25, 2014 at 11:01 am #

      Sean…all locked breech slides will move a “fraction” of an inch at pressure spike. That’s Newton’s Action and Reaction at work. The barrel is pulled backward along with the slide…still locked together by the upper barrel lugs…and at 1/10th of an inch of rearward movement, the bullet exits. The slide continues to pull the barrel backward, and the barrel starts to drop. By 1/4th inch of travel, the barrel completely disengaged from the slide.

  2. John Travis December 25, 2014 at 4:57 am #

    Sean…all locked breech slides will move a “fraction” of an inch at pressure spike. That’s Newton’s Action and Reaction at work. The barrel is pulled backward along with the slide…still locked together by the upper barrel lugs…and at 1/10th of an inch of rearward movement, the bullet exits. The slide continues to pull the barrel backward, and the barrel starts to drop. By 1/4th inch of travel, the barrel completely disengaged from the slide.

  3. Jason October 17, 2017 at 7:07 am #

    Great article! Appreciate the technical depth, as I was just wondering about this myself.

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