Im on the fence of should I sell mine and go with a 16 inch barrel
Only if they state that. As the above video states, you need to register, turn them in, reconfigure to turn them into something else, or not comply with their new rules. Tomorrow, when they change their rules again, the same applies.
With a pistol, many states āallowā concealed carry. With any other classification of firearms, you cannot legally CC. SBRs, SBSs (short-barreled shotgun), AOW (all other weapons), and destructive devices (usually rifles over .50 cal, grenade launchers, mortars, explosives, etc.) are heavily regulated by the ATF, and require registration and payment of $200 to obtain a tax stamp. Also there is an additional FBI background check that usually takes 6 months or more, which includes obtaining your fingerprints. That last part is not an issue for me, as I have probably been fingerprinted more than most criminals.
The other issues with NFA items is how you are āallowedā to travel with them, and transfer them (sales and heirs, etc.). As I do not own any NFA (that I am aware of), I do not know all their rules about them.
It is just one more control over our lives. Ostensibly it was because criminals could more readily conceal an SBR or SBS, than a full-size rifle or shotgun. The ATF definition, here, of a pistol does not even mention length of barrel. It does state that it is designed to be held in one hand, and a couple of other factors, none of which involve size.
I have more links to the ATF site pages, here, on another thread, that provide more information.
This is really helpful, @Dave17 ā thanks for taking the time.
If you just use the buffer tube then its not able to be shouldered and is still a pistol?
Weāre not there yet, but itās starting to sound like āIf you like your rifle you can keep your rifle.ā
Very valid points
Iām not trying to short cut a law. Just very aggravated that I wanted so long waiting for this too happen and it does 6 months after going the pistol route.
Everybody finds the legal means around laws, especially unconstitutional and stupid laws. Recall the 1970s with the Tax Shelters? The ATF definition of pistol, the link in my post above, fits these pistols they are now claiming to be SBRs. An SBR is a firearm defined as a rifle, with a barrel less than 16".
Just me. I like the idea of a sbr. Like an adjustable stock. Question is this only a build thing? Iāve got the patience of a badger so just want to buy one. Is this possible?
It sounded like that the pistolās caliber could be a consideration for what is considered an SBR and what is a pistol with a brace? Itāll be interesting to see what they come up with in their final documents.
That is not in the definition of an SBR. Go to the ATF site and read it. I have links to pertinent ATF pages on this thread here.
Very helpful. Thanks
So if you attach the lower with a brace to an upper with a 16" barrel or longer, youāre fine, because then itās a rifle (I think I got that part correct).
But where does the measuring of the barrel stop? So from the chamber to then endā¦what if I have a compensator or suppressor attached that make a 13" barrel 16"+? Does that count as barrel length?
I think they can, but only if pinned or welded. My buddy has a 14.5" barrel on a Bushmaster AR that has a 1.5" flash suppressor that is welded. It came that way from the factory. It was legal at 16" so equipped.
That was exactly what I have a short barreled Bushmaster with a 3ā inch welded flash hider!
Bad news? Below attachment forthcoming from ATF.
Thanks @Jeffrey97, doesnāt seem like the ATF addresses it in those āobjective factorsā maybe it will be in whatever āclarificationā they createā¦(or maybe it addressed in another ATF ruling).
Maybe weāll get lucky, but Iām not holding my breath.
Thanks @Virgil_Hā¦but then how can I properly maintain/clean it? 
Do you know if your buddy had any language from ATF or Bushmaster on the requirement for it to be pinned/welded?
That is a great question about the cleaning. He bought that rifle about 18 years ago before we worried about such things. He has no such paperwork. Sorry sir.
Hereās the Federal Register I got in the email.
https://www.federalregister.gov/documents/2020/12/18/2020-27857/objective-factors-for-classifying-weapons-with-stabilizing-braces?utm_campaign=CMMG%20Inc.%20Statement%20(TfFiE5)&utm_medium=email&utm_source=070720%20-%20Insider%20-%20Segment1&_ke=eyJrbF9jb21wYW55X2lkIjogIldGTWJGMyIsICJrbF9lbWFpbCI6ICJyZXY3NDVAaWNsb3VkLmNvbSJ9
Thanks @Jeffrey97, Iāve submitted my comments. The sad thing is that there are only about 13,000 comments so far when hundreds of thousands of gun owners own these braces. We need to speak up if we donāt want our rights taken away.