BCM SBR Registered lower

I’m waiting for my tax stamp to be approved on my BCM SBR lower. It looks like you folks registered it as having a 10.5" bbl and I wanted to put a BCM 11.5" bbl on it. What do I need to do wait for approval then send ATF notice I intend to increase the bbl by an inch or do I need to do anything.

Thanks

Depends on how permanent the modification will be. If it’s likely to be permanent then send them an amendment letter once it’s approved. If not, then I’d wait until it is permanent or you’re thinking of selling a particular configuration.

One thing you should realize though is that there is no such thing as a SBR lower. A machine gun does have a registered lower because of the wording used in the law. A SBR though is a lower manufactured with a short barrel attached. (And yes, that manufacture can be later in life when a barrel is cut down or the upper changed).

It is my understanding that once you have the approval you can go up in size, but not lower. So if you have an approved Form1 with 10.5" you can go up to 14.5". If you listed 14.5" you cannot go lower with making an official change. YMMV

Thanks Gunz

That makes sense to me. I plan to slap an 11.5" BCM upper on and call it good. Of course now I’m drooling over the lightweight 11.5" upper BCM has as a teaser on their website. I have a hammer forged upper in the safe waiting for the tax stamp to be approved. What is the break down on the weight of all three BCM 11.5" uppers?

Go to www.ATF.gov and call the NFA branch. Per my conversation with them not long ago you must send an amendment letter for each bbl less than 16" whether you are going shorter or longer. Check to be sure…remember ignorance is not a legal defense. I would rather measure twice in this context!

Sparky

Sparky

Thanks for the info. I will do that and report back! So it sounds like I need a letter. Have you done this before? Just curious how long it might take.

I have not but I was talking to them trying to get my ducks in a row as having multiple uppers of different SBR length and 1 registered lower and 1 or more UNregistered lower (constructive intent) can cause major problems and I am too far into a new career to go to jail over ignorance. I always like to know the tiny details before embarking on these projects. I have basically concluded that, when I get started on this deal, I will no lowers that are not registered SBR lowers because I plan to build several different uppers of different lengths because depending on the inspector/agent you get on inspection (I am FFL) you COULD wind up with your balls in a sling…what I said above about going to jail! Just thought I would pass on what they told me! Always best to check, IMO! Hope it all works out well!

Sparky