View Full Version : Hypothetical question about an illegal modification

Hunter Rose
December 20, 2004, 10:40 AM
A friend asked me the other day about modifying a 1911 into a full auto. Now I have tried figuring it out every way possible (including detailing my officer's model, to check the interaction of the parts), and I keep seeing a big problem (other than the legal issue). If you modified the sear to allow the hammer to fall without a new trigger pull, wouldn't the weapon simply bang away as soon as the slide was dropped?

Not looking for "how to" info, and not interested in breaking the law. Just trying to make sure I'm understanding how the inner working of the 1911 function...

December 20, 2004, 11:43 AM
I know a person who had a 45 go full auto because of some defective parts somebody else had put in the gun and he said he would not want to go through it again

Hunter Rose
December 20, 2004, 12:37 PM
That was kinda my feelings when my friend asked me about it: how in the HECK would you control it?!?!?!?

December 20, 2004, 01:17 PM
Hello everybody.™

There have been some books on converting Brownings and 1911s to full auto on FortLiberty, but they're illegal. Why?

Because the BATFEA enforces legislation that forbids semi-auto to full auto conversion.

BTW, the whole thread might be illegal, discussing how to convert to full auto, which is why wise people keep their mouth shut :eek:

December 20, 2004, 01:28 PM
Books (and threads) about how to make a gun full auto are NOT illegal, due to the First Amendment. You can buy them anywhere.

Hunter, simply removing (or filing the top off) the disconnector would do it, in theory. Disconnectors are what makes a gun NOT full-auto by disconnecting the trigger from sear, so the sear can restrain the hammer despite the full aft position of the trigger.

In reality, it doesn't really work because the hammer will chase the slide up and usually not hit the firing pin squarely. But 1911s are notorious for the occasional burst if the disconnectors are too worn or something else is well out of spec in the lockwork. I've seen it a couple of times at matches.

Finally, because the disconnector also insures that the slide is fully in battery, such a modification is rather unsafe because the gun could fire too early and result in a case head failure.

Maybe with porting you could control such a modified 1911, but every time I've seen one double or triple the muzzle rise was not controllable. For those last two safety reasons (plus the obvious legal one) I'd never mess with this.

Hunter Rose
December 20, 2004, 01:33 PM
Again (and I'll say it as often as necessary): I have no intention of actually doing this. It was brought up in conversation, and got me to thinking about the mechanics of the pistol...

Handy: so I was kinda right in my first assumption: modifying whichever important part would result in something very unsafe (although I'll admit I was thinking of the sear). Thanks!

Jim Watson
December 20, 2004, 02:15 PM
There were selective fire Spanish Stars; and Trejo in Mexico made a 1911 styled .22 in selective fire. There are patented full auto conversions for Colts.

Filing on existing parts won't get it done, all that can do is simulate the wear or breakage that sometimes causes a gun to "run away." It takes new construction to make it work reliably and safely.

December 20, 2004, 02:42 PM
I've seen a few examples of full auto/select fire 1911 conversions in a SAR article.

Each had some way for the slide to trip the sear as it went into battery. A couple were a very crude hook-like device on the slide. Another, iirc, had a ramp machined into an interior surface of the slide to trip a hidden auto sear.

To do it right, you'd have to add some parts to keep the hammer from simply riding the slide.

December 20, 2004, 02:51 PM
I never understood the whole full auto pistol thing, the only aplication i could think of is that a cop or soldger could kinds poke the gun around the corner and blast a bunch of rounds around to maby hit or scare the bad guys? I mean how could you acuratly aim the thing?

December 20, 2004, 02:59 PM
In general, regardless of gun type (long arm, pistol, whatever), in a full auto gun, or select-fire in full auto mode, there is some mechanism that keeps the hammer from dropping until the action is finished/shut into battery - not sure what this part or tooth on another part is usually called. Having said that, many illegal modifications that have been done in the past (as I understand things) - homegrown full-auto conversions - don't use such a sophisticated fire control system - they instead rely on the crude "slam-fire" method you describe, which works in some guns (I dare say most) but not in others, although probably not 100% reliably. Converting to a "slam-fire" full auto is easy, if one were inclined to become a criminal - I'm not and don't recommend it to anyone - you just file off the disconnector. Let's repeal the stupid '86 ban on new machineguns, so that the prices will drop and people can actually afford to buy one (with proper licensing). Where's your diety named Bush now gburner? He can't even do such a simple, obvious thing to help the RKBA.

full-auto pistol = worthless anyway, EXCEPT possibly something like a calico "pistol" in .22lr with 100 round rotary drum - I could see that being useful in certain (stealthy) situations, where concealment precedes the mission.

December 20, 2004, 07:54 PM
Its never happed to me and I have tried but several friends that have shot it did get a couple of rounds of several times, and from seeing that I can tell you that I wouldnt ever want one.
First round in the chest, second in the OVER head and 3rd some where in the next town.
A mac 10 full auto was enought for me.

James K
December 21, 2004, 11:52 AM
Destructo6 is correct. Any auto firing has to be positive (not just hammer followdown) and take place only after the gun is fully in battery and locked.

That means the gun must have some sort of auto sear which will be disengaged by the final 1/10" of slide movement after locking has taken place. "Slam fire" like that used in blowback SMG's won't work since the pistol slide is not heavy enough to allow the gun to be used as a straight blowback with the .45 cartridge, even with the advanced primer ignition of the SMG.

Aside from complexity and legality (and the political issue of police use of full auto weapons), we need to address the role of a pistol, which is generally seen as a reasonably light and compact weapon for personal defense or general police use. Since the factor most against the idea of a full auto pistol, even with a shoulder stock, is that it is not controllable, we need to keep the definition of a pistol in mind. If the gun is to be an acceptable pistol, it will be too light for FA fire. If it is to be a mini-SMG it is too bulky to be a feasible pistol.


December 24, 2004, 10:28 PM
Back in the middle 50's a classmate had a Marlin 22 cal rifle which was worn out in a way that allowed it to fire a full 7 round magazine lickety split. I thought it was neat at that time. Later, one of the gun rags in the 60's told of a .45 that went full auto on the firing line. Supposedly the rapid recoil kept the shooter from being able to release the trigger and the muzzle rose a bit with each successive shot. The 7th and last round hit him in the side of the neck. Certainly not something I'd care to experience.

December 25, 2004, 10:36 AM
We make a conversion utility piece for Glock pistols that allow for semi and full auto fire. We designed them with the Glock 20 and 21 in mind, for sheild men in the stack. And let me tell 'ya, if you haven't practiced with them weekly you'll get a big muzzle climb and a nice suprise.

For a specific role they are fine. For play they are just silly.

3 weelin geezer
December 26, 2004, 11:23 AM
Read the thread a little while down about tony. If you want to see a full auto pistol, search for "Sickboy" and check out his video of his glock 18 in the philipines. I like the face he makes. :eek: