[dborns]

I’ve done numerous builds using Uzi parts kits but it’s been awhile. I recently bought a Sarco M16 parts kit, and when going through the items that came with it, I found the auto disconnector and trigger.
Like I mentioned, it’s been awhile since I did the other builds, but I thought I recalled being told to get rid of the parts that could let you build anything as an automatic. I’m not going to use those two parts, but they’d be nice to have unless they’re illegal to possess?

 

[Trunk Monkey]

I’ve done numerous builds using Uzi parts kits but it’s been awhile. I recently bought a Sarco M16 parts kit, and when going through the items that came with it, I found the auto disconnector and trigger.
Like I mentioned, it’s been awhile since I did the other builds, but I thought I recalled being told to get rid of the parts that could let you build anything as an automatic. I’m not going to use those two parts, but they’d be nice to have unless they’re illegal to possess?

I don't know the exact wording but I think the ATF has ruled that if you have the parts it's constructive possession.

 

[dborns]

That’s unfortunate.

I didn’t think about it before posting, but the BCG is auto also.....

 

[Bigcat]

That’s unfortunate.

I didn’t think about it before posting, but the BCG is auto also.....

The auto BCGs are fine and common.
Many folks like their extra weight for tuning purposes when running carbine gas systems on 16 inch barrels.

 

[Sniper03]

dborns
No problem with having the Bolt Carrier Group. Some new ARs come with them and companies sell tons of them. IMO having the other auto components to possibly assemble an auto rifle can be a problem as TM mentioned. *Intent/Constructive Possession. IMO *Best not to have any around! What one agent might overlook and not think as significant another might not!

03

 

[microadventure]

here's how that goes:

legal semiauto rifle
auto parts kit
instructions for putting auto parts in legal semiauto rifle

possession of any two constitutes constructive possession. the capability = the deed, and your busted!

 

[PANDEMIC]

The auto BCGs are fine and common.
Many folks like their extra weight for tuning purposes when running carbine gas systems on 16 inch barrels.

What's the difference between regular BCG's and the auto ones?

 

[Gatoragn]

What's the difference between regular BCG's and the auto ones?

Weight, more metal in a full auto BCG, so it is heavier.

 

[PANDEMIC]

Weight, more metal in a full auto BCG, so it is heavier.

Does that help with reducing wear and tear when putting alot of rounds through it?

 

[austin92]

I’m not fluent with AR’s but isn’t the m16 receiver cut different? With ak’s you can have the trigger group as long as the hole in the receiver isn’t drilled. I’d think that would be the same with how your receiver is cut.

 

[Gatoragn]

Does that help with reducing wear and tear when putting alot of rounds through it?

Helps smooth out the cycling, decreases the likelihood of the BCG short stroking, etc.

 

[c3shooter]

 

[Trez]

Heres the post to the A1 I built: https://www.firearmstalk.com/threads/retro-a1-build.131982/

I "neutered" my disconnector by cutting the tail off of it and I bought a new semi-auto safety selector... The auto sear is the big "no-no" part your not allowed to have...

 

[W.T. Sherman]

What's the difference between regular BCG's and the auto ones?

on a "regular" or semi-auto BC the bottom back of the bolt carrier is cut out or slotted or otherwise is severally shorten so it won't be able to trip the auto sear

 

[Txhillbilly]

Heres the post to the A1 I built: https://www.firearmstalk.com/threads/retro-a1-build.131982/

I "neutered" my disconnector by cutting the tail off of it and I bought a new semi-auto safety selector... The auto sear is the big "no-no" part your not allowed to have...

The auto sear isn't illegal to own,but it is a NFA Class 3 item and you will need to do all the paperwork,background check,and tax stamp before you take possession of it.

 

[dborns]

All good info thank you. It was hard to do, but I discarded everything this morning on my way to work. In different cans so it wasn’t bagged up for someone to find. I already have a lower built for it so I didn’t need any of the lower parts anyway.
Now I’m just waiting on a barrel as the one I bought is to large in diameter.
I also need to research the color of the originals bc the lower is brand new and if like to make it look as roached as the rest of the gun.

 

[Bigcat]

Does that help with reducing wear and tear when putting alot of rounds through it?

"M16 BCGs" became popular when so many ARs had 16 inch barrels with Carbine gas system (so extra dwell time vs the 14.5 inch barrel this gas system was designed for). .. that is unless the barrels gas hole was adjusted for that (that is made smaller and it often wasnt) the rifle would be overgassed.

An overgassed rifle is usually not a huge problem as...undergassed is worse which can cause short stroking so it might affect your reliability in a more direct way... mostly overgassing increases wear on components , especially the bolt ...but most PPL dont shoot enough to ever notice.

The heavier ("auto") BCG can be used just like a heavier buffer to slow things down to adapt to overgassing.. a lot easier than putting in a new barrel (with a smaller gasport)

In general though AR15 BCGs are perfectly fine... since many ARs dont NEED their system slowed down..some are close to short stroking anyway.
Especially when they shoot soft ammo like PMC Bronze of Tula and are tuned closer to a service rifle (that is for M855 and M193).. this will often result in undergassing and short stroking.

Very early in my AR15 "career" I bought a rifle.. it had been assembled all with quality components.
But it would short stroke with PMC Bronze almost every shot and Tula ( which at the time I was still using also)
It needed hot ammo to function reliably (PMX Xtac 55gr is what I used.., a quality M193 clone)

After examination I found:
An H2 Buffer (so 2 steps heavier than normal Carbine buffer) and a "full auto" BCG.
Replaced the Buffer with a Carbine buffer and the BCG for a regular Ar15 BCG and so solved my issue.
(This took me a lot of research since I was a noob back then)

Here is a graphic of what the ejection pattern should look like to tune your ammo and rifle for each other:
On my primary "GO" rifle (which unlike my trainers does not have adjustable gas) when I shoot hot ammo (Wolf Gold) I am usually at 3- 2:30 (which I tolerate)..
The Ammo I shot the most (Wolf Military Classic 62gr) is right around 3:30-4

 

[Wambli]

The auto sear is the ONE part that you can not have and the SARCO kit does NOT include it. If it did they’d be in jail and you too for having an unregistered one.

 

[Sniper03]

Austin

To answer your question about the Receivers being different. Yes they are! Beside the extra hole for the Auto Sear Pin. More of the inside of the rear of the Receiver is cut out to accommodate the auto system. Especially the aluminum ledge area of the Rear of the Receiver directly under the Take Down Pin and forward.

03

 

[BlackGuns4Fun]

Pretty good explanation here.