Auto Burst Trigger Systems

[MichaelEzekiel]

The externally mounted trigger systems that claim to give a semi automatic rifle full auto fire rates, are they effective, and are they legal? Has anyone used one, and if so what are the pros and cons?

 

[Wildalaska]

They actually allw ya to bump fire, and I for one find it childish and unnnerving

WildbutthatsmeAlaska

 

[stans]

Sustained high rates of fire tend to be hard on barrels that are not chrome lined. Also, I think it is hard to bump fire with accuracy. I view these devices as just another gimmick designed to part the shooter from his or her money.

 

[standingbear]

truthfully....they are 5 dollars worth of material that sells for 40 dollars. The videos make them look like fun but they are absolute junk.

I had bought one for a ruger 10/22 once. all it was ..a flat wedge held on by a piece of spring steel that looped around the trigger guard. the wedge went in the slot between the front top of the trigger and the receiver gap so when you released the trigger, you inadveradly touched that wedge and it pressed the trigger again. my finger couldnt get off the trigger until the mag was empty because it kept firing. it went right into the trash...plus it scored a nice line in the trigger guard where it held it in place.


dont believe the video, its made to get you to waste your money and buy it.

 

[Jim K]

That is one version, there are/were others, including one with a hand crank. I agree with the others that they are not effective and can be hard on the gun. The big drawback to me is that no matter that they are legal, if someone hears what he believes to be machinegun fire, the tendency is to call the cops. With a bit of (bad) luck, you could end up in jail while the cops or the DA send for an expert to say that the thingamajig is legal. Then the cops are ticked, so they just change the charge to reckless endangerment or something and toss you back in.

Worse yet, there may be some states or jurisdictions where it is NOT legal. Those sellers cite Federal law; your local laws are your problem.

Jim

 

[1911Tuner]

Legal Burst

I remember the hand crank device that Jim mentioned...It was known as
"The Activator" and was pure junk. I know of one instance of an Activator
destroying a Colt AR-15 upper receiver when it fired the rifle out of battery. The shooter was lucky that he wasn't ruined too. Don't know if the "Static-Firing" devices that operate off the gun's movement are any better or safer...but IMO...It's not worth the risk. The legal hassle is also a possibility, as Jim mentioned. Depending on the jurisdiction and the attitudes of the local politicos toward firearms in general...it could be an interesting experience, to say the least.

WA probably nailed it with the simplest term. "Childish and unnerving."

 

[TexasRifleman]

I too bought one in my teenage years for a Mini 14. Junk. Couldn't hit the broad side of a barn with the stupid thing. Plus it only worked about half the time and kept coming loose from the trigger guard.


I have to disagree however with the premise that one can destroy a gun. All they do is pull the trigger very quickly. If using one of these causes a rifle to fire out of battery, then that firearm has some serious issues long before this hand crank thing came along.

 

[buzz_knox]

They'll certainly burn out the barrel faster due to the increased level and duration of heat. Most barrels aren't designed for sustained fire like this.

 

[DESERTRATONE]

It's a felony to possess in California.

 

[TexasRifleman]

Barrel burnout I'll buy, but blowing up things? Nope.

 

[1911Tuner]

Blowups? Oh! Yes!

Should anyone want to see if an AR-15 will fire out of battery, it's easy to
test. Pull the charging handle back a little until the bolt starts to unlock and pull the trigger. So will an M-1 Garand or an M-14/M1-A. Try it and see...
and then consider how the crank device worked versus the automatic sear
on an M-16.

With a selective-fire M-16, the auto sear becomes the disconnect when the selector goes to the third detent, and cams it into position to capture the upper hammer hook...and the semi-auto disconnect is cammed back out of the way so that it can't catch the lower hammer hook. The bolt carrier trips the top of the automatic sear, releasing the hammer after the bolt goes into battery.

To put it simply...the hammer release is mechanically timed. If the auto sear
pin is located just a few thousandths farther to the rear than it should be, the hammer will release early...just AS the bolt goes to battery. Increase that mislocation by just a few more thousandths, and the hammer will release
before the rotating bolt is fully locked into place. When that occurs, 60,000 pounds of uncontained pressure is vented into the upper receiver, and a catastrophic failure results.

When the trigger is pulled by a device that isn't mechanically timed, and operates independently of the bolt's position...and the only timing of the hammer release is the speed that the operator can turn the crank...you absolutely can have ignition out of battery.

Or, as Ripley said: "Believe it...or not."

Cheers all...and goodnight.

 

[Jim K]

Hi, guys,

Not too sure about that firing out of battery on the M16/AR-15. True, the hammer could drop early under some circumstances, but the firing pin cannot reach the primer unless the bolt head is fully locked. That feature is totally independent of the position of the hammer. The only way it could be negated is by doing some really dumb things to the parts, like leaving out the cam pin.

The M1 and M14 (and other rifles) are also well protected against out-of-battery fire and most reports seem to be based on a misunderstanding of the term. A poster on another site repeatedly stated that his M1 often fired out of battery, and asked how he could tell when it did. I guaranteed him that if his rifle really fired out of battery, he would darn well know it.

Jim

 

[1911Tuner]

Battery

Mornin' Jim!

While I'll agree 101%that the AR-15 is designed to prevent firing out of battery, I'll go on record stating that under certain circumstances that they will...and I know of one that did...or at least that was the final call by Colt.
When the rep that I talked to learned that an activator crank had been on the rifle, he chuckled and told me that he knew of a half-dozen other rifles that had been damaged by the device.

On the one in my experience, the side of the upper was blown out and the bolt was almost fully rearward and frozen in place so badly that I had to remove the buttstock and the buffer tube and beat the bolt forward with a hammer so I could break the rifle down. There was obvious damage to the bolt lugs and carrier, and the hammer pin was bent. The timing had to have been just perfect, since the stop ramp under the rear of the firing pin didn't arrest the hammer like it should have.

he had been using commercially loaded ammunition, but it wasn't mil-spec...
so primer sensitivity may have played a role. IIRC, it was Federal, which has
a reputation for fairly soft primers...but I may be wrong on the brand. It happened in 1985...so my recollection may be a bit fuzzy.

The lower receiver and bolt carrier were lightly damaged, but salvageable, and the barrel was undamaged. Since Colt wouldn't touch it under warranty, we ordered an SGW Upper and put the rifle back together for him. Since the SGW upper was set up for the M-16 push-pin, we had to get one of those offset pins used to mate an M-16 upper with an AR-15 lower. As far as I know, the rfle didn't give any more trouble...but he did toss the crank in the can.

Oh, what a tangled web we weave, when first we practictice to dink around with a semi-auto...

 

[Mac's]

Hello all...Many years ago there was a gizmo that would change the timing of the mechanism so that the rifle would fire one round when the trigger was squeezed and a second one when the trigger was released. It was advertised for a Mini 14 and they had a photo of the part next to the trigger group. Of course, I built one from the photo and it did actually work as advertised. In my case, the recoil would cause the trigger to hit my finger before I could move it and do a second double tap. A four round burst every time and actually fairly accurate. It was not "bump firing" or slam firing and I was holding the rifle tight in the normal shoulder position.
The idea was to increase the distance between the trigger hook and the sear hook. The hammer could get away from the sear without getting caught by the trigger hook when the trigger was released. For the Mini-14, it was 1/2 of a heavy duty 9/16 staple stuck between the sear and thr trigger. On AK's, it's a thin, flat strip of metal cut from a soda can. No modifications at all to the rifle and the technique will work on any spring loaded sear. (Mini 14's, AK's, FAL's, etc)
Yes, it's very hard on rifles not designed to run on full auto. The really scary part is that if you squeeze the trigger and hold it in, there's another round waiting to go when you let go of the trigger. A real dead mans trigger.
Of course, it's illegal now. The laws used to say one round fired for every cycle of the trigger but there are two strokes for every trigger cycle. In and out. I can't quote the laws but they've changed it to cover this method.
Oh well.
Keep yer powder dry, Mac.
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