TexasCHLforum.com

You can fire a Browning M2 with one hand. You can fire an M777 Howitzer with one hand. You could fire a "pistol M700" with one hand. There isn't a clear line, which renders the effort to delineate between a firearms that can legally have <16" barrels and firearms that cannot practically impossible. Further, the longstanding recognition of the utility of short, handy guns means that such weapons have been common for well over 150 years. The practical distinction never existed. Finally, ownership of a rifle and a chop saw, lathe, or even a hacksaw in the case of a shotgun is constructive possession.

The SBR provision of the NFA is so vague as to be unenforceable. The suppressor portion is ludicrous and should also be struck, but at least it can be legally defined.