XD Talk

ArmyGuy45 · 12-31-2010, 02:56 AM

How do those different bolt carriers make it so you can make it full auto?

I thought the "full auto or burst" was in the trigger assembly and thats its. Didnt matter on the BC.

John A. · 12-31-2010, 10:38 AM

Quote:

Originally Posted by ArmyGuy45

How do those different bolt carriers make it so you can make it full auto?

I thought the "full auto or burst" was in the trigger assembly and thats its. Didnt matter on the BC.

This topic has been beat to death over and over and I have no wishes to continue it, but I will answer this question since it appears genuine.

In a M16, the bottom of the M16 carrier is what strikes the auto sear when the bolt is almost all the way closed (enough so the timing will allow it to be by the time the hammer swing hits the firing pin) and if you notice on the AR15 carriers, the bottom of the carrier is milled back, and thus would preventing that action from taking place if an M16 fire control group were installed because there is nothing there to contact the sear.

In a slightly different style of machine gun (Lightning link and DIAS) it would require the carrier to be to Colt SP1 AR15 carrier specs so the bottom of the bolt would contact the lightning link paddle ear to pull the link backward, thus releasing the disconnect.

So hopefully you can see how important having the correct bolt carrier installed would determine a full auto or semi-auto depending on the configuration is just as important as any of the other fire control parts... all the parts work together. Mix-n-match and you're going to have a mess.

Fdxpilot · 12-31-2010, 10:52 AM

Quote:

Originally Posted by ThumperMX113

A lot of companies do. Even earlier in this thread, which was a couple years ago, it was mentioned that Colt does sell their rifles with M16 BCGs. I think everyone was more concerned with them installing one themselves vs buying a rifle with one in it. For what it's worth all of my BCGs are M16 groups. How can you tell from that picture that it's a M16 BCG? Don't you need to see the bottom?

If you look closely, you can just see the cutout at the bottom ends at the same place as the top of the carrier.

ArmyGuy45 · 12-31-2010, 11:04 AM

Quote:

Originally Posted by John A.

This topic has been beat to death over and over and I have no wishes to continue it, but I will answer this question since it appears genuine.

In a M16, the bottom of the M16 carrier is what strikes the auto sear when the bolt is almost all the way closed (enough so the timing will allow it to be by the time the hammer swing hits the firing pin) and if you notice on the AR15 carriers, the bottom of the carrier is milled back, and thus would preventing that action from taking place if an M16 fire control group were installed because there is nothing there to contact the sear.

In a slightly different style of machine gun (Lightning link and DIAS) it would require the carrier to be to Colt SP1 AR15 carrier specs so the bottom of the bolt would contact the lightning link paddle ear to pull the link backward, thus releasing the disconnect.

So hopefully you can see how important having the correct bolt carrier installed would determine a full auto or semi-auto depending on the configuration is just as important as any of the other fire control parts... all the parts work together. Mix-n-match and you're going to have a mess.

So you have to have the BC group and the trigger assembly for it to work. I thought it was just the trigger you needed. I know with my M4 I could make it "full auto" by placing some cardboard in the right place . So I thought it was just the trigger but what you said makes sense now that I think about how it works.

Thx for the input!

John A. · 12-31-2010, 12:00 PM

Armyguy45, I don't know anything about using cardboard, but the M16 carrier is a key component with the M16 fire control group and function.

ArmyGuy45 · 12-31-2010, 12:13 PM

Quote:

Originally Posted by John A.

Armyguy45, I don't know anything about using cardboard, but the M16 carrier is a key component with the M16 fire control group and function.

If you put cardboard in the trigger assy it makes it full auto cause the hook cant grab the spot to stop after 1 shot or 3. I dont know the names of them anymore. I thought thats all it took. I didnt know there was also metal needed on the BC group.

John A. · 12-31-2010, 12:24 PM

I see what you're saying now, but all that does is defeat the disconnect and allow the hammer to swing freely and ride the bolt home and hope/pray that it has enough momentum to light the primer when it gets there which is less than ideal for reliability and for other reasons.

In effect, it could also allow an early detonation of the primer before the bullet is fully seated in the chamber too. An unsupported case can easily rupture causing a nice kaboom in your eyeballs as well.

That's not the way a (full auto) M16 works.

And coincidentally, would be creating a new machinegun if you're talking about that in an AR15 and not one of uncle sugar's M4's which are already machineguns and exempt from this topic.

ArmyGuy45 · 12-31-2010, 12:41 PM

Quote:

Originally Posted by John A.

I see what you're saying now, but all that does is defeat the disconnect and allow the hammer to swing freely and ride the bolt home and hope/pray that it has enough momentum to light the primer when it gets there.

In effect, it could also allow an early detonation of the primer before the bullet is fully seated in the chamber too, causing an unsupported case and nice kaboom in your eyeballs as well.

That's not the way a (full auto) M16 works.

When I did it. It became full auto until the mag ran out, no matter if it was on single or burst. After that I just took the cardboard out and ran with burst!

RyanH · 01-03-2011, 01:21 PM

Quote:

Originally Posted by ThumperMX113

Thank you for that form, appreciate it.

I know this a old thread and post but... A LOT of lower receivers made today are in fact low shelf and completely capable of the addition of a RDIAS.

Just because they are "low shelf" does not make them full auto ready. You would still need to drill the auto sear holes.

John A. · 01-03-2011, 01:31 PM

Quote:

Originally Posted by RyanH

Just because they are "low shelf" does not make them full auto ready [reference: RDIAS]. You would still need to drill the auto sear holes.

A RDIAS does not require any additional holes in an AR15 receiver and if someone did make a (new) auto sear hole, would create a new machinegun. (felony)

That's not how a DIAS or LL works.