Full Auto Fire Control Group In AR-15?

P

Palmetto-Pride

New member
What parts of a full auto fire control group are legal to have installed in a regular AR-15? Any? None? I know full auto bolt carriers are ok is it a combination of different things or is it just the auto sear that would make it illegal?
 
Maybe the hammer if none of the other parts are installed (still, not a good idea). However, anything that will permit the gun to slam-fire will be illegal. There are other factors to consider - simply possession of a set of M16 full auto parts and an AR could potentially get you in trouble.
 
Last edited:
The autosear cannot be installed without drilling the hole for the pin and machining a full cut to half of the rear of the receiver. Full auto hammers can also cause malfunctions and should not be installed.

You will notice that an M16 receiver is distinctly different from even an old school low shelf AR 15 receiver.
 
It varies with where you are. Some places don't care what parts are in the gun, as long as it does not fire full auto. Some places have laws about "machine gun parts". In those places it is possible to have "illegal" parts in your semi auto only rifle.

The ATF at one time declared the auto sear, (all by itself, no other parts or gun needed) to be legally, a machine gun.

Amazing what the boffins in govt service can do, isn't it?

Safest thing, no M16 parts in your AR. M16 parts in your AR, but NOT capable of full auto ought not to be any concern of anyone, but in some places, it is, due to state (and maybe local) laws.

I know one state that the way the law is written, it not only prohibits private ownership of machineguns, it also prohibits ownership of machine gun parts. Technically, even unservicable parts used as a paperweight could be illegal there.

Most folks don't know, and can't tell the difference in the AR parts, but rest assured, if you are ever in a situation where the legal system gets interested in what is inside your AR, they will bring in an expert who can tell.
 
It is a weird set of ATF rules.. It confuses me truthfully. I bought an Hk MR556 and it has a fully auto hammer factory installed. I guess they got away with it because the barrel has a notch (easily removed) that won't allow the 416 BCG to be used in it. Truthfully I would say if they wanted to push it, the ATF could do what they wanted as far as prosecution. Who knows...


That's why I will leave this to the more knowledgeable members to answer.
 
I believe only the DIAS (Drop-In Auto Sear) is what needs to be registered to the ATF. You can have a FA/M16 BCG, Low-shelf Lower receiver, and FA trigger; None of those actually make your AR15 fire in full-auto/select fire so they are not illegal. The DIAS is what allows Select Fire. The other FCG parts are also not regulated and registered in any way. You can walk into any gun store and buy a M16 BCG or FCG, or buy a stripped lower receiver with the Low Shelf online.

Of course this may depend on your local and state laws as well so do your own research. I have No issues with it where I live. I have Spikes Tactical lower receivers with the Low shelf and M16 BCG's in some of my rifles.
 
If you install all of the M16 full auto parts, but not the sear, the gun can still be made to slam-fire. This is illegal.

There is no reason to install M16 fire control parts in an AR. They are not even as good as a number of upgraded AR fire control parts which can be used to give this rifle an incredible trigger. Basically, spend your efforts building an AR that most military folks would envy rather than making something that is questionably legal, or flat-out illegal.
 
Parts dont drop into most AR15s. The SP1 will accept them, i think?? Photo of M16A1
M16A1_20080820_02.jpg
[/URL][/IMG]
M16A1_20080820_01.jpg
[/URL][/IMG]
 
Most AR15 lowers will accept all of the full-auto parts except the sear. The SP1 will not accept the sear, even if you drill a hole for the pin, A portion of the lower receiver would have to be milled out to install the auto-sear.

The SP1, however, will accept a DIAS with no modification, but I believe most lowers being made today would also accept the DIAS. This is why you cannot own an unregistered DIAS and an AR, or you may be in constructive possession of a machine gun.
 
^ The safety/selector tumbler looks suspiciously absent. I don't remember the full auto parts using that particular disconector either but I could be wrong.
 
It's just the angle - you can clearly see the selector switch on the left side - you are forgetting that the round part of the tumbler is in front of the lever and flush with the receiver.
 
The ATF at one time declared the auto sear, (all by itself, no other parts or gun needed) to be legally, a machine gun.
Click to expand...

Is that still the case? If so, how is it you can buy an auto sear at brownells with no paperwork at all? I know they're intended as replacement parts for existing NFA M16s but then it would count as a part not the actual MG.

As far as I understood the lower itself is the machinegun. Having all full auto parts in your AR15 is legal as long as it does not have a lower with the necessary cuts and pin holes for the auto sear. But the sear itself is not the machinegun, just the cuts and pin hole for it are essentially.
 
Lots of things can be a machine gun with regard to an AR15. A modified lower receiver, possession of a pre-81 DIAS and an AR15, possession of an AR15 and a full set of full-auto M16 parts, possession of a post-81 DIAS, next.......

possession of a CAD program to 3D print a DIAS.
 
next.......

possession of a CAD program to 3D print a DIAS.
Click to expand...

I hope not, I mean it's not a complicated mechanism, I have a small but thorough machine shop in my basement, just because I could manufacture many things that would be highly illegal does not mean that's what I am, or intend to be doing.
 
I hope not, I mean it's not a complicated mechanism, I have a small but thorough machine shop in my basement, just because I could manufacture many things that would be highly illegal does not mean that's what I am, or intend to be doing.
Click to expand...

Don't worry. The key wording in the law is "readily convertible to fire fully automatic" Having to mill your own parts is not "readily convertible" even by ATF standards.

Now a 3D printer makes things much easier but for now comments like Skans' are nothing but jokes and snide remarks. In the future however, who knows.
 
must be the camera angle, but in the top photo it sure looks like the rt leg of the hammer spring is missing.:D
 
You must log in or register to reply here.
Back
Top