Auto-sear question

[hitdank]

As i can see inside the gun, what an auto sear does is push down the disconnect once the bolt moves foward completely. You can try this by holding down the trigger, cock the hammer, and use your finger or a screwdriver to push the disconnect down and the hammer will drop. The ak works in a different way though.

[george223]

As i can see inside the gun, what an auto sear does is push down the disconnect once the bolt moves foward completely. You can try this by holding down the trigger, cock the hammer, and use your finger or a screwdriver to push the disconnect down and the hammer will drop. The ak works in a different way though.

Interesting. Didn't think of that and now the shape of the wall hanger makes sense.

[ar15barrels]

No, but your rifle is always full auto or safe from then on.
You can't use a selector on these drop in devices.

WTF are you talking about?

An M16 fire control group with a DIAS or an actual sear gives you auto, semi-auto and safe positions on the selector.

[ar15barrels]

The "Drop-In Auto Sear" does not require drilling the third hole, or any milling.
The sear assembly has two parts.
The housing rests in the milled pocket of the receiver and the hinged sear then functions the same as if it was riding on pin in the third hole.

4 parts:
Housing.
Sear.
Spring.
Pivot pin.

[ar15barrels]

I think the only advantage that the drop in auto sear gives you is that you don't have to drill a hole in your lower receiver and that it is easily removed. I'm guessing that you would need to remove the disconnector and would still need the M16 bolt carrier and hammer. The AR would not function as a semi-auto with this setup.

You use an M16 hammer, trigger, disconnector, selector and carrier with a DIAS.
You will have safe, semi-auto and auto settings.

An auto sear (standard or drop-in) holds the hammer until the carrier trips it as the carrier is closing when you are in auto.
When you go into auto position on the selector holds the disconnector down so that the auto sear can control the hammer instead of the disconnector.

[ar15barrels]

As i can see inside the gun, what an auto sear does is push down the disconnect once the bolt moves foward completely. You can try this by holding down the trigger, cock the hammer, and use your finger or a screwdriver to push the disconnect down and the hammer will drop.

Wrong.

In the M16 design, the auto sear holds the hammer hook on an M16 hammer.
The auto sear releases the hammer when the carrier is close to being closed.
An auto sear does not get anywhere near close enough to the disconnector to interact with it.
The selector holds the disconnector down when in auto position.

1:30 to 3:03 in this video:

[RickD427]

4 parts:
Housing.
Sear.
Spring.
Pivot pin.

Correct. I was actually referring to the principal parts where the housing provides all of the support for the sear, as opposed to the receiver, but you still need the pivot pin and spring.

The key here is that the pivot pin does not travel through the lower receiver, and hence no third hole is needed.

[tabascoz28]

An auto sear with an m16 selector allows for safe, fire and auto. The trigger is actually different. You can actually find a 3 position selector on brownells and a full auto assembly and the auto sear, but you have to be LEO to order the latter 2 parts I think.

A drop in or link only has safe and fire, the fire in essence is full auto until you take the finger off.

[NoHeavyHitter]

A registered DIAS is far superior to a registered M16. The owner of the DIAS can use it across an entire collection of suitable AR's for only a single tax stamp. Being easily removable permits the gun to be made a legal semi-auto which removes NFA restrictions against transport across state lines (without prior authorization). This is essentially the same kind of thing that the HK guys do by having a registered trigger pack that can be used in many different guns.

[EBR Works]

An auto sear with an m16 selector allows for safe, fire and auto. The trigger is actually different. You can actually find a 3 position selector on brownells and a full auto assembly and the auto sear, but you have to be LEO to order the latter 2 parts I think.

A drop in or link only has safe and fire, the fire in essence is full auto until you take the finger off.

This is correct. We have a post sample Lightning Link that drops into a Colt SP1 without mods to the FCG.

M16 FCG for full mill/drill conversions are available from different sources including Brownells & GunBroker. IIRC, illegal to possess in CA without FFL/SOT/DWP.

We have not done a DIAS post sample since a mill/drill conversion is dead simple with a milling machine. DIAS requires M16 FCG to function just like a mill/drill conversion & gives you safe/single/FA. Will also work with safe/single/3 rd burst FCG.

We have one M16 with safe/single/3 rd burst FCG. It’s a poor design compared to HK since you might get one, two or three rounds. The cam mechanism doesn’t fully reset after each single shot or burst. The HK design is superior & does fully reset every time.

[champu]

As i can see inside the gun, what an auto sear does is push down the disconnect once the bolt moves foward completely. You can try this by holding down the trigger, cock the hammer, and use your finger or a screwdriver to push the disconnect down and the hammer will drop. The ak works in a different way though.

[TKM]

For a while there I had a machine gun holding my shoes on.

https://www.thetruthaboutguns.com/when-a-shoe-string-is-a-machine-gun/

[The War Wagon]

Good morning ATF.
How"s the coffee today?

PA is a NFA/Class III legal state.

CA however...

[sigstroker]

An auto sear with an m16 selector allows for safe, fire and auto. The trigger is actually different. You can actually find a 3 position selector on brownells and a full auto assembly and the auto sear, but you have to be LEO to order the latter 2 parts I think.

You do not. Other than the RDIAS, you just have to know where to get them.

A drop in or link only has safe and fire, the fire in essence is full auto until you take the finger off.

A RDIAS is drop-in, and they work safe, semi, and full. A bare Lightning Link is safe and full only, but you can get parts to make it run semi also.

[george223]

You use an M16 hammer, trigger, disconnector, selector and carrier with a DIAS.
You will have safe, semi-auto and auto settings.

An auto sear (standard or drop-in) holds the hammer until the carrier trips it as the carrier is closing when you are in auto.
When you go into auto position on the selector holds the disconnector down so that the auto sear can control the hammer instead of the disconnector.

Ya, I forgot about the 3 position switch. Old age does that to you. Thanks for correction. My lowers only allow 2 position without mods.