TexasCHLforum.com

My understand of AR pistol vs rifle was that the receiver had to have been designated as a "pistol" when manufactured, otherwise if the barrel/overall length falls below ATF rifle rules it is subject to being classified as a short barreled rifle and requires a stamp.

Turns out...there is an "other"....

I'm guessing its something like this:
https://franklinarmory.com/products/com ... xo-series/