How does m16 select fire work

Note that during a SEMI trigger pull you have to overcome the tension of the burst disconnector spring which adds to the trigger pull. This is different than the 3-way burst fire control group where the burst disconnector is never locked out. The selector cam also contacts the semi-auto left disconnector and locks it out. Note : The first trigger pull when BURST is selected may fire 1, 2 or 3 shots depending upon the starting position of the burst cam, but all subsequent trigger pulls will fire 3 rounds if the trigger is held to the rear.

Also, if you release the trigger quickly it is possible to fire less than 3 rounds. If you do fire less than 3 rounds the next trigger pull will complete the 3 round burst. For example, if you pull the trigger quickly and fire only 1 round, the next trigger pull will fire no more than 2 rounds. In full AUTO the selector cam rotates the auto sear into position to capture the hammer. The selector cam also contacts both disconnector tails locking them out which prevents them from capturing the hammer so the rifle will continue to fire while the trigger is pulled to the rear.

The already heavy AUTO trigger pull is even heavier because both disconnector springs are compressed during the trigger pull.

In summary , when the burst disconnector is locked out you get semi-auto fire. Lock out the semi-auto disconnector and you get burst fire. Lock out both disconnectors and you get full auto. It differs from the 4-way kit in three ways. A 3-way burst kit uses a standard full auto selector so it has no 4th position, the burst disconnector has no "tail" to ride the selector cam so the burst disconnector is always free to ratchet the burst cam and engage the hammer and the auto sear is slightly different--the 4-way auto sear has a thin, curved selector cam follower.

You can convert an M16A2 to normal full-auto mode by following the instructions in the next section. Burst Disconnector Hammer Hook The BURST position will then function as full-auto because the burst disconnector will never capture the hammer and the rifle will fire as long as the trigger is held to the rear. The SEMI function is not affected by this modification. I recommend you purchase a replacement burst disconnector for the modification and leave your original burst disconnector alone so you can switch back to 3-round burst.

Specialized Armament sells the 3-way burst disconnector. You can quickly swap a normal and modified burst disconnector by pushing the trigger pin halfway out from the right side of the receiver just enough to free the burst right disconnector.

Swap the disconnectors and push the trigger pin back into position. Convert 3-Way Burst to 4-Way If you already have a 3-way burst kit you can convert it to a 4-way by installing the four Colt 4-way specific parts: Auto Sear, both Disconnectors and the Selector. I can no longer find a source for the 4-way selector. Installing the 4-Way Fire Control Group Removing the Selector Stops I knew the standard M16 selector stops were a problem because they prevent the selector from traveling to the 6 o'clock position which is required to get to AUTO, the 4th selector position.

I saw pictures on the web of the DPMS 4-way kit that does not require the removal of the selector stops and it comes with an optional label that fits under the selector lever. The selector lever is raised to clear the selector stops.

The Colt 4-way kit requires the removal of at least one of the selector stops. I used a Tactical Machining AR jig to hold the lower receiver in place during the machining.

The end mill left perfectly smooth, shiny ovals where the selector stops were removed. My M16 lower is in mediocre shape and I plan to have it refinished anyway. I used some Birchwood Casey Aluminum Black to temporarily cover the bare metal where the selector stops were.

Install a standard trigger spring. The silver disconnector spring goes on the right side of the trigger, the black disconnector spring goes on the left. The double hook disconnector goes on the right side of the trigger, the single hook goes on the left.

You can cut a spare trigger pin in half to make an assembly pin to hold the trigger and disconnectors together during assembly. This makes it much easier to drive the trigger pin through the trigger and disconnectors.

As you drive the trigger pin in during assembly the half-pin will be driven out the other side of the receiver. Next assemble the hammer group. Put the burst cam spring inside the burst cam. The spring extension goes into the slot in the burst cam.

The spring extension goes in first so it will fit deep into the burst cam slot. Install the burst cam and spring onto the right side of the hammer. Make sure the cam spring is fully seated and flush with the cam. The ridge on the burst cam goes outward. With the cam installed install the hammer spring. If you don't use an assembly pin insert a punch through one of the lower receiver's trigger holes and through the trigger assembly to hold everything in place while you fit the trigger pin in from the other side.

Take your time and move the punch around while pushing the trigger pin and it will eventually slide through. Applying some downward pressure with a finger on the disconnectors will often help get the trigger pin through. Put the selector in place. The burst disconnector's forward hook makes the hammer install a little more difficult.

Use a thin punch to depress the rear of the burst disconnector to move the burst disconnector's forward hook to the rear to give you room to fit the hammer in front of it. Ideally the only modification to an M16 lower receiver required to install this Colt 4-way selector kit is to remove one or both selector stops. Due to differences in manufacturer specifications your M16 may or may not need additional modifications.

I installed the trigger assembly in my David Company M16 lower and found my first problem. A burst trigger is wider than a normal trigger to make room for the two disconnectors. My M16's trigger well wasn't wide enough to accommodate the extra wide trigger. It rubbed the right side of the well. When I installed the hammer I realized I had another problem. The burst cam was making contact with the forward edge of the fire control group well.

It was so tight the cam would not turn. I had to mill out the forward edge and corners of the fire control group well to make room for the burst cam. I got all the parts installed and ran the function check and found problem 3. I could not pull the trigger when AUTO was selected.

After closely examining the trigger to selector interface I realized the selector cam had a small nub that was hitting the right side of the trigger.

Colt has been informed of the milling defect. If your Colt 4-way selector is defective and has the nub you can replace it, mill off the nub, or simply remove some metal from the right side of the trigger where it meets the selector to allow the trigger to be pulled see photo below.

A grinding wheel did the trick in short order. The left side of the trigger was left unmolested because it contacts the selector in the SAFE position to lock the trigger. As it moves forward again, the carrier catches the top of the sear in the DIAS assembly and releases the hammer. Unlike the recent bump stock fiasco, BATF grandfathered unregistered sears made prior to November 1, M fire control parts are legal to purchase and own, though we nary see a point unless you have an M You cannot legally possess one if you own an AR A further legal problem is compounded because none of these sears were engraved with a serial number to substantiate a date of manufacture.

In court, the burden of proof is placed on the defendant and, thus, the prosecution presume the sear was made well after the grandfathered date. This makes the possession of this little part akin to owning an unregistered machinegun. This is a drop-in part to convert a commercial AR into a fully automatic firearm. There are a few caveats regarding the use of this device, however.

There are several manufacturers making kits to allow select-fire with the Lightning Link by modifying real M fire control parts to function with the Lightning Link in an AR These lowers can work if the shelf is milled away. Again, milling will be required to make it fit. If you have a commercial bolt carrier, or even an M carrier, these will need to be milled to work with the Lightning Link. Lastly, the Lightning Link is a fragile piece of hardware.

In semi-auto mode, the hammer is cocked as the bolt carrier moves rearward. When the carrier returns to the forward position, the hammer is held in this position by the sear located on the forward part of the trigger catching in the sear notch, on the hammer.

Using one in a modern rifle requires some tuning and other work. Because the trigger is being held back, the disconnector hook is pushed forward and in position to catch the hammer, preventing it from following the carrier forward.

When the trigger is released, the hammer moves from under the disconnector hook and is caught by the trigger sear in the hammer sear notch, making it necessary to pull the trigger for each shot. When the trigger is held rearward, the sear is below the arc of the hammer notch. The only thing holding the hammer in the cocked position is the disconnector.

The Lightning Link works by pulling the disconnector to the rear and releasing the hammer. The upright portion sits between the rear takedown pin post of the upper and the bolt carrier. When the bolt carrier strikes the top of the link, the bottom portion swivels to the rear, moving the body of the link rearward and releases the hammer from the disconnector hook.

As the trigger is held rearward, the movement of the bolt carrier continuously cocks the hammer and forward movement of the carrier strikes the upright of the link as the bolt locks in battery, releasing the hammer, and firing the rifle. The sear stops the hammer in the cocked position when the trigger is released. At first glance, the Swift Link appears to be a little more robust than the Lightning Link and seems to be more user-friendly regarding compatibility with different lower receivers.

The only other requirement seems to be the use of an M bolt carrier. It looks like it would work much like the Lightning Link by depressing the disconnector when the bolt closes and releasing the hammer to enable full-auto fire.

It showed up on a few internet forums and appears to have an origin as the result of a Freedom of Information Act request submitted to the ATF with regard to the October shooting at Mandalay Bay in Las Vegas. Questions remain as to whether the shooter actually made the device and used it, or if it was the image of a prototype found on his computer. Inspired by images of the Swift Link, Winslett was searching for suitable materials in order to make a version of his own.

Yes, that is a bent-up coat hanger, properly registered as a post-sample machinegun. We really wish , of these were made and registered before May of ' As you can see, there are a variety of ways to convert an AR to full auto. These prices are escalating in step with everything else full auto as there are only a finite amount in the NFA registry.

In a similar sense, if assault charges were pressed on you and you claimed self defense, the burden shifts to you to demonstrate you acted in self defense. The prosecution is then burdened with proving this is not the case. The issue is that the pre exemption applies to the original taxation, it does not apply to post transfers. Courts have repeatedly held that if a pre DIAS is transferred after 81, then it is subject to any current regulations for transfer.

Bradley, F. Cash, F. Otherwise an old shovel that could be hammered into an AK receiver could be registered too. I lost all of my guns in a house fire and yet to buy any more except a pistol and a shotgun but when I had my ar15 I shot it pretty fast so why gamble on the possibility of jail for conversion of a rifle. What a bunch of hypocrisy they twist all the laws not justlaws about guns around so we get confused about it all…ITS all about the money guys. Iv looked at all the different ways to convert and im sure someone will find a different way to do it just to say it works..

By Mail. Facsimile Transmission. Form 2 may also be submitted for approval via facsimile transmission provided that the licensee has filed and affidavit with the NFA Division in accordance with ATF Industry Circular Submission electronically. Receipt by NFA Division. Are you sure it makes sense cause If a sot can manufacture a post 86 machine gun for LE and govt. In order to have a faster rate of fire than real factory full auto, all you need is a positive trigger reset which allows steady positive trigger pressure to release the hammer after the bolt is far enough forward not to interfere with the hammer stroke.

Actually it dumped a 10 shot mag. The trigger was replaced. I totally agree that many of these laws are so twisted and ineffective on crime. BUt with the current cost of ammo and the increasing media hype that makes the world think that every AR is a machinegun, What is the need for running a full auto?