One SBR lower for ANY upper?

I recently "built" a Colt Commando pistol and am planning on sending in my Form 1 with the $200 tax to SBR this lower and not worry about the ever changing AR Pistol laws.

I finished this one with a factory new Colt M4 Carbine lower receiver and swapped out parts for a SB Tactical SBA3 brace, Geissele SD-3G trigger, Geissele Super 42 H2 buffer and braided spring. For the upper I started with a factory new Colt 6933 Commando 11.5" upper and added a BCM Gunfighter Mod 3 charging handle and Midwest Industries MI-20M drop in 2 piece free float M Lok handguard.

I have another pistol upper I recently put together in 6.8 SPC on a lower that is marked "multi cal."
This is where my question comes in. I was under the assumption that once I have a SBR registered lower I can pin practically any upper onto it I want, so long as the caliber of the upper matches the caliber engraving on the lower. Is that correct, and if so, can the "multi cal." lower have any caliber upper on it? If that's not the case, can I Form 1 my 5.56 marked Colt and run my 6.8 upper on it if I wanted?


Thanks in advance

Cory

 

That makes perfect sense now, thank you. I've had locals tell me it doesnt matter what upper you run but nobody ever mentioned the fact you need to keep a/the similar upper on hand the lower was originally registered for. I think it'd be a good idea to bring that upper to the range if i plan on shooting a different upper then too.

 

Certainly have that other upper handy. And I would feel better with the “multi” marked upper just because some cops don’t know the laws that they are trying to enforce and that can cause headaches. “Multi” would immediately be an indication that it’s ok to swap barrels.

 

I’ve never been asked to show my documentation to anyone either.

 

That part kinda annoys me. I got mine set up for .300 on this specific upper I don't now like so either I need to just keep it and not worry, or get an identical higher quality clone.
So my advice: pick a good upper you will want forever to do the Form 1 on.

 

I also don't know anyone who has, or know for sure anyone who has, but I keep all my photocopied docs in a red nylon envelope with the gun because who knows.

 

It's pretty much impossible to make a permanent change to an AR.
In other words there will never be a need to notify ATF of any change to caliber, OAL, bbl length, etc.

 

mistake...

 

I know, that's why "annoyed" not "kills me," or "ruins my gun." But the .300 upper is just in the safe waiting to be improved or traded out while I mostly run the 9 or 5.56 upper on it.

I know it's just more paperwork to submit, keep track of etc., wish I had been a tiny bit less impulsive as I wouldn't have to do that, and keep track of it.

 

If you switch out the upper on your SBR to a different caliber or barrel length, there is no law or regulation requiring you to maintain the original upper or to notify the ATF of your change. What MachIVshooter is saying is simply a recommendation, since the ATF requests that you notify them of any permanent changes to caliber or length. And you certainly don't need to bring your unused original upper to the range with you; the only reason to do so would be if you're worried about coming into contact with overzealous and uninformed LEOs. But like others in this thread, I've never once been asked for my NFA paperwork, even when I've come into contact with police officers while out shooting my NFA stuff in the woods.

 

All good points guys. I think I'll Form 1 my 556 Colt lower instead of the "multi" Aero one, so I can keep the Colt Commando with matching receivers.

Basically, I should be safe keeping copies of the documents with me at the range. There is typically nobody at the range I shoot at anyway so I'm not terribly worried about it anyway.

Now is it true that once you have a registered SBR that the ATF can come do a checkup at your house whenever they want, or is that all hearsay?

 

So if you have a registered sbr for 12 inches and want to notify in a letter to ATF permanently modifying it to 10 inches, does ATF officially respond in some format? Or do they just keep the letter in case someone calls them up?

Thanks

 

Paying a tax (which is what an NFA stamp is) does not forfeit your fourth amendment rights regarding searches.

 

I only know one guy that has been asked. Once it was retrieved he said it was like they didn’t know what they were looking at anyway.

 

Yes.

 

I form 1ed my "multi" lower as a 9.5" 5.56 SBR. I have since had it rebarreled as an 11.3" .300 Blackout. I just kept the old barrel so if the ATF ever wants to see it I can prove that it can be put back into it's original configuration. There is always the possibility I may have the money in the future for a separate complete upper for it. I thought about writing them, but no real reason to, so better off just leaving them be, like I want them to leave me be. As long as you go by the rules, you're covered should they ever come for a look-see.

 

One of the issues is that the letter of the law can make a mock-up to get an accurate OAL illegal and you sometimes have to guess. When I first got into the NFA game I included the muzzle device in OAL (funny how removable stuff on one end counts but not the other). Also I measured one shotgun of the same brand before building my Lupara and found the ribs and vents were different on the second gun of the same model. I wanted to end on a rib for structural and cosmetic reasons.

I sent a letter for both of them with corrections and got a simple acknowledgement in the mail 3 years later. I would not do so for a modular type firearm like an AR.

Mike