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Material: Stainless steel
A drop in auto sear work requires:Low Shelf And M-16 bolt carrier and m16 hammer or m16 selector
Product Description
Drop-In Auto Sear, Full Transferrable Class III/NFA Registered
Broadhead Armory BA-15 Registered Drop-In Auto Sear, Class III/NFA Fully Transferrable Machine Gun Sear
what is a drop in auto sear
When Colt decided to sell a semiauto-only civilian version of its AR-15 rifle, it had to make a number of changes to the design of the lower receiver to prevent full-auto fire control parts from being used. These changes would make a semiauto AR receiver legally distinct form a full-auto one, and thus not a machine gun in the eyes of the law. Among the changes Colt made was to remove the auto sear, along with its pin and mounting holes.
Now, at this time (and still today) the possession of full-auto fire control parts was not regulated. Owning an unregistered machine gun receiver was illegal, but the internal parts were not machine guns by themselves. The DIAS, or drop-in auto sear, is a small device that was invented to duplicate the function of the original auto sear without needing a mounting pin. It could simply be “dropped in” to a semiauto AR receiver and if used in combination with some of the full auto fire control parts it would result in a fully automatic rifle.
How Does a drop in auto sear Work
A DIAS doesn't require a third pin hole, though some receivers will require some milling. When a DIAS is installed in an AR lower, the hammer is cocked by the bolt carrier as it moves rearward. The carrier pushes the hammer down and the sear of the DIAS grabs the hammer.
The phrase “automatic sear” refers to the device in a gun that changes a semi-automatic weapon into a fully automatic one. Burst mode is another possible outcome of the conversion.
What does the firearm’s fully automatic mode do? The firearm’s fully automatic mode continues firing until the trigger is set free. This means that this firearm can fire several shots at once. What does the firearm’s burst mode do? When the trigger is pulled, the burst mode firearm fires three to four shots at a moment.
So, this metal device is mounted in the firearm for a fully automatic system, . When the firearm is set to fully automatic, the sear just lets go of the striker, allowing the weapon to shoot constantly and consistently.
How To Install a drop in auto sear
One of the first methods of converting an AR to fire full auto is to install a part known as a Drop-In Auto Sear, or DIAS. The DIAS requires an M-16 hammer, selector, and bolt installed in the rifle. The “Drop In” appellation refers to the end-user not having to machine the lower to accommodate an auto sear, as a secondary auto sear is part of the DIAS.
When a DIAS is installed in an AR lower, the hammer is cocked by the bolt carrier as it moves rearward. The carrier pushes the hammer down and the sear of the DIAS grabs the hammer. As it moves forward again, the carrier catches the top of the sear in the DIAS assembly and releases the hammer.
Transferable DIAS are referred to as Registered Drop-In Auto Sears or RDIAS.
The kit includes a master jig of hardened tool steel, a repair Part A of hardened steel, a repair Part B of hardened steel, a replacement roll pin, a replacement movement spring, two proper sized drill bits, a tightening Allen wrench and basic instructions.
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