Hello all. Newbie to the forum here. I have a general question regarding oal measurement of my build.

Current setup:
Aero m4 lower
Aero parts kit
Geissele maritime bolt release
Geissele 2 stage trigger
K2+ grip
Law folder gen 3
Amazon sb3 brace
Bcm mk2 recoil mitigation system
Bcm  mk2 bfh11.5 upper
A2 flash hider
Eotech exps 2

What I’m looking to understand is how this would be measured. Is it with the rear folded or not? Assuming if it is folded I have myself a truck build. If not folded I guess I am looking at just another “firearm”.

Thanks

If you are building a pistol, it doesn't matter.
If you are building an SBR, bbl length less than 16" or OAL of less than 26".
If you are building a rifle, bbl length of at least 16", OAL of at least 26".

For barrel length:
The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to
the furthermost end of the barrel or permanently attached muzzle device. Permanent methods of
attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver
soldering, or blind pinning with the pin head welded over. Barrels are measured by inserting a dowel rod
into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the
furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and
measured.


For OAL:
...if the firearm has a folding or collapsible stock, the overall measurement is to be made with the stock extended...


Currently there is a nationwide injunction against ATF Rule 2021R-08F .......but that may be appealed.

If it is appealed, and SCOTUS rules in favor of ATF, then you may have an NFA firearm.

Awesome. Since the build was a lower transferred as other it can be a pistol. So it sounds like I’m in the clear. Thank you for the response!

Yes, and if you build a pistol first you can swap a long barreled upper on it any time you wish.

If not actually built as a pistol first, lie.  Nobody will know but you

rule was vacated, not an injunction.  

https://www.sigsauer.com/blog/federal-court-rules-that-pistol-stabilizing-braces-are-now-legal

and if aft wants to appeal, the appeals court that it would go to has already ruled recently on violations of apa.  

so if pistol braces become no bueno again it will be after another round of notice of proposed rulemaking, comment period, final rule.  aka not before the next demonrat potus gets to nominate aft head.  

so, roughly 5 years unless the Republican Party manages to snatch defeat from the jaws of victory.  again.