Semi auto conversion to "full auto"


John Peddie
September 14, 2006, 04:07 PM
We had a major school shooting in Canada yesterday.

Two dead (including the shooter) and 11 more injured, several seriously.

Newspaper reports claim that the shooter was using a rifle which had been legally purchased as a semi-auto and later converted to full auto.


(1) Is it technically possible to do such a conversion of a sporting rifle?

(2) If so, would it be something an average person skilled with tools-say a machinist-could do, or would a gunsmith be needed?

If it's feasible, then can someone briefly summarize what needs to be done?


Fully automatic weapons are illegal in Canada (military and possibly police excepted). I have no intention of doing such a conversion.

My only rifle is a single shot bolt action Mossberg .22 dating from the 1960's and it would not be a candidate anyway.

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Fred Fuller
September 14, 2006, 04:31 PM
Not really an appropriate question for the Shotgun Forum, I think...

But, by way of being helpful-

Yes, it is indeed possible to convert a semiauto design to selective fire/full auto. It is also not legal and thus not a proper subject for polite conversation (the government decries conspiracy theorists on the one hand but is happy to charge defendants with the crime of criminal conspiracy on the other).

It was once done with the Remington 1100 shotgun in experiments for the Department of Defense by Remington, in fact (to drag this thread kicking and screaming back on topic). That is a history lesson, not an exercise in criminal conspiracy, you can see pictures of the Model 7188 on pp. 329- 336in Thomas F. Swearengen's _The World's Fighting Shotguns_ (Alexandria, VA: TBN Enterprises, 1978). Famous designer John M. Browning's first fully automatic design was in fact a converted lever action. That is a history lesson, also.
"Browning converted a Winchester 1873 lever-action to an autoloader by using the action of the gases at the muzzle. A machine gun using this same operating principle was built in 1890 and 1891. From this work evolved a machine gun design ultimately built and sold by Colt as the Model 1895 machine gun, popularly called the "Browning Potato Digger" because of its downward arcing, gas-operating piston system."

Beyond this, deponent sayeth not. Sorry.


September 14, 2006, 04:55 PM
Newspaper reports claim

The first mistake was going off of THAT information.

The other was asking how to do it on The High Road. No one knows, and if we did we wouldn't talk about it. :)

But to give you the benefit of the doubt, it's certainly possible but with the weapon he's shown holding in the photos, and we'll assume it's what he used, full auto would have provided no real benefit and the cost and skill involved would have been way beyond what the kid appears to have been capable of.

September 14, 2006, 05:17 PM
Most people don't know the difference between full auto and a semi auto being used rappidly.

There is also the possiblity that he was bump firing the rifle.

From what's been pieced togeather online, the guy defined looser geek/wanna be goth vampire loony. While it may be possible to convert the beretta cx4 to FA, it is highly doubtfull that he would have had the skills, tools, or savvy to do so.

John Peddie
September 14, 2006, 05:48 PM

Thanks for the info.

My little high school competition .22 hasn't been shot for over 35 years, but I figured that if a conversion were possible, someone on this site would know.

Again, my disclaimer that I have no intention of doing such a thing and have no gun to do it with in the first place.

Problem is that newspaper reporters who write about guns generally know as little about their subject as those who write about airplanes involved in crashes.


I know that this was not a shotgun question, but will add that THR is the most informed (and well-mannered) site on the Net, and if a shotgun conversion were possible, then logically, a rifle conversion would be too.

Just did not want to wade into a "letters to the editor" exercise with a major Canadian newspaper before I tapped your expertise and that of the others here.

Thanks again.


Fred Fuller
September 14, 2006, 06:26 PM

You're welcome.

If this were still a free country then concerns about the consequences of mere speech would not prevail over an honest search for answers to relatively simple mechanical questions. But alas, such is no longer the case here.

And in any properly run country, an attack like the one tragically promulgated upon the students and staff of your school would have been answered instantly by a random nearby citizen, properly armed and trained, taking the criminal assailant under effective return fire. As it was, it was necessary to wait for 'the proper authorities' to arrive and do what needed to be done. Such is life in our modern world. My estimate is that it will get worse, not better.

More's the pity.

I neglected in my first response to offer my sincere sympathy to the innocent hapless victims involved in that tragedy, and their families. I apologize for that oversight and hope to remedy it now.

lpl/nc (who really doesn't like to go where he can't legally CCW, which unfortunately includes the university campus where his wife teaches)

September 14, 2006, 08:55 PM
Fully automatic weapons are illegal in Canada (military and possibly police excepted).
Not quite correct. They are fully-automatic firearms legally owned by civilians although the ownership has been grandfathered for some years now.

The shooter used a Beretta CX4 Storm and any suggestion that it was converted to full auto is no more than media speculation.

And for mandatory shotgun content the shooter (now thankfully burning in the fiery furnace) also had a Norinco 12 gauge and a Glock 21.
September 14, 2006, 10:15 PM
Go to it has some articles on converting semi to full, it sais that its impossibe... incorrect, I didnt tell you this... ;) lol but really yes you can and its easy, with a semi automatic there is an interupter to make it shoot one and then retract the fireing pin and such, all you really have to do is take out the interupter (part of the bolt somewhere usually), and some other safety things. I have freinds that have done it to stuff like .22's and hunting rifles just for fun. All I beleive youd need is a gunsmithing book or something, it wouldnt tell you specifically how to do it, but you could figure it out from parts and expeiriance.

Also, to those who said that Nobody on THR would give response, im sorry, just like to show off.

Sorry about the shooting, it sucks that some ppl go out like that.

It was probably just a semi, with a shaky finger. Like the Berreta extrama2 can go so fast you wouldnt beleive it isne FA

Dave McCracken
September 14, 2006, 10:16 PM
When I saw the media crap about this tragedy all I could think of was that ONE armed and trained civilian coulda shut this bozo down before the body count got into the teens.

A half dozen armed and trained people on that campus could have done as much good as a SWAT team and been a lo0t closer to boot.

Armed law abiding civilians are free cops pragmatically....

Brass Fetcher
September 14, 2006, 10:55 PM
The really good thing about criminals is that they are always looking for the 'easy' way to do anything.

For example, since shooting a gun with any precision takes practice (and is 'hard' to do), criminals can't shoot a gun and hit anything, in general.

If there was any full-auto involved, I would bet you a dollar that the loony bought/stole it, as opposed to putting any thought at all into converting one.

RE the conversion of semis to full, if it were easy, then the BATF would not allow semis to be sold in such a configuration.

To answer the question of can a sporting rifle be modified: in theory, yes. In practice, no. I say this because designing parts of the right material/dimension requires a good deal of proficiency with Mechanical engineering and making the parts requires a skilled machinist and expen$ive machines and the time to run them. Finding a machinist to make a simple non-gun widget is getting harder and harder - finding one to do something obviously illegal - don't bet on it.

Automatics have a disconnector, in addition to the basic parts found on a semi. The disconnector keeps the hammer cocked even if the trigger is held down - until a few moments after the bolt is in battery and the gun is safe to fire. Finding space for such a device in a gun not intended for it ... would be a definate complication.

Full auto = sound of money flying downrange. :)

September 14, 2006, 11:56 PM


John Peddie
September 15, 2006, 09:06 PM
As I said I'd never do such a conversion even if I had something to convert. But this sad incident is sure to reawaken our anti-gun lobby...already has, actually.

Best to know the terrain from you experts before challenging someone in the press.

For those of you who may not know, Canada has a mandatory registration system for all "long guns" and you have to be licensed to buy ammo too. AND show your registration card anytime you buy guns or ammo.

Where's the Second amendment and the NRA when we really need them here?

We have no legal protection from the "anti's".

A mass shooting in Australia led to the virtual confiscation of pump and semi guns a few years ago, leaving hunters with only singles and doubles.

Much as I love my double, I still want freedom of choice.

NO laws or registration system will/can prevent a psychopath from creating havoc, be it with guns, knives, explosives or whatever.

Thanks again.


September 15, 2006, 10:01 PM
Dave McCracken said:
When I saw the media crap about this tragedy all I could think of was that ONE armed and trained civilian coulda shut this bozo down before the body count got into the teens.


I'll have to respectfully disagree. I submit that if Canada had Conceal Carry, loserboy would have either a) been deterred from carrying out his evil, or b) even if undeterred, the rampage could have been quickly ended by one (or more) CCW'ers long before the body count grew to more then one handful of fingers.

When you can't tell the sheep from the goats the BG's are forced to think that everyone could be a goat.......with horns.

Silly gun control laws do nothing more then create an environment where evil can work unfettered killing and maiming the innocent until time it takes for the Cavalry to come riding in over hill, figure out what's going on, formulate a plan and then begin to neutraulize the threat. In the meantime, the innocent bleed and suffer while the body count rises.

Dave McCracken
September 16, 2006, 02:25 PM
Not that much in disagreement, Scout.

In Israel, everyone can carry. Darn near everyone is a military veteran. The Intafada had the bright idea of having terrorists going into Israeli areas toting large knives and stabbing up all the housewives, Talmud Scholars and other seemingly defenseless persons.

It didn't work well, since many of those housewives and scholars were packing. Thus, the Suicide bombers started up.

Gun control causes crime, not reduces it. Expecting gun control to stop crime is like expecting making it harder for sober people to buy cars will stop drunk drivers.

September 16, 2006, 03:03 PM
Also, to those who said that Nobody on THR would give response, im sorry, just like to show off.

Interrupter? Part of the bolt?

Semi auto operation is achieved utilizing a disconnector to stop the operation of the mechanism between each shot. As a matter of fact, A full auto weapon(with the exception of open bolt) actually lock the hammer in the rear postition between shots as well, untill the bolt is fully locked into the chamber. At this point, from my understanding, a sear "trip' lever(HK term) then disengages the sear from the hammer and another shot is then fired. To simply remove a part, albeit called a disconnector or "interrupter', would cause most semi-automatic weapons to fire at an uncontollable rate, possibly resulting in cartridge ignitions before the bolt was "home". Ask anyone who has had one break on a 1911. Essentially, there is no way to stop the firing cycle untill the magazine is depleted.

This synopsis is, of course, based on the Browning type of trigger operation, which is included in such weapons as the G43, M16, AK47, BAR, etc. I'm assuming the Beretta has nothing new on this concept, as this is by far the most widely used.

Most weapons have a variety of parts that differ between the full and semi autos. For example, literally all "moving" parts housed in the recievers in the M16 family are different than those found in the AR-15. The Century Arms HK-G3 and CETME pieced together clones not only have new selectors, triggers, disconnectors, and hammers, but the sear trip lever is removed, and the surface of the bolt carrier they ride on is machined out.

Keep in mind, it is absolutely illegal for a person to modify a firearm to shoot more than one round for every pull of the trigger, unless you have a Class 3 manufacturers liscense, or a Class 1 with a government letter of permission. But to say it can't be done is just silly,as any person with the ability to slightly more than field strip a firearm can unsafely and illegally create a "machine gun".

September 16, 2006, 03:12 PM
I guess since this is posted in the shotgun forum, it should be said that the Remington 1100/1187 series of shotguns also utilize the Browning trigger system. Though its hard to fathom a full auto 1187:what:

B yond
September 18, 2006, 12:05 AM
what aboot slam fires? I was always undr the impression that if you could get the firing pin to stick fully foward any semi-auto rifle would slam fire and thus be full-auto. Am I wrong?

September 18, 2006, 03:32 AM
A full-auto shotgun? I can't imagine why. Even rifles in full auto mode are next to worthless unless you're surrounded and simply want to spin around and hit as many people as possible. Worthless because so inaccurate to the average crazed shooter upper. Give me a good semi auto for school-shooting-up any day over a full auto. Unless you're specially trained in machine gun usage you'll hit more bullies and prom queens with a semi.


September 18, 2006, 06:23 PM
what aboot slam fires? I was always undr the impression that if you could get the firing pin to stick fully foward any semi-auto rifle would slam fire and thus be full-auto. Am I wrong?

No, you are correct, as the "open bolt" Thompson M1A1 smg and the M3 Greaseguns of WW2 had the firing pin molded into the bolt face. you have to consider though, the possibility of an open breach detonation is very pausible. And, if the weapon fired every time the bolt closed on a "closed bolt" action, you would not be able to control the weapon with the trigger. It would fire whenever you racked the action and continue untill its feed supply ran out.

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