hawk-eye, have you read any of ATF's letters or FAQ online about this topic?
https://johnpierceesq.com/can-you-add-a-vertical-fore-grip-to-an-ar-pistol/
Above is a link to the website of a lawyer who has an active practice with NFA guns and gun trusts.
He quotes a 2011 letter from BATF that plainly says that part of the definition of an AOW is that it must be a concealable weapon-- which ATF regulations say is 26 inches overall length (using the same measurement that Congress itself wrote into the laws for short rifles and shotguns.) So ATF and this gun-rights attorney both conclude that if your AR "pistol" has an overall length of 26" or greater, EVEN WITH any arm brace collapsed or folded to its shortest position, it can't be an AOW. It's not concealable. Too big to easily conceal = "not an AOW" and therefore NO "making an AOW" would happen regardless of what kind of grip you have up front.
https://johnpierceesq.com/can-you-add-a-vertical-fore-grip-to-an-ar-pistol/
Above is a link to the website of a lawyer who has an active practice with NFA guns and gun trusts.
He quotes a 2011 letter from BATF that plainly says that part of the definition of an AOW is that it must be a concealable weapon-- which ATF regulations say is 26 inches overall length (using the same measurement that Congress itself wrote into the laws for short rifles and shotguns.) So ATF and this gun-rights attorney both conclude that if your AR "pistol" has an overall length of 26" or greater, EVEN WITH any arm brace collapsed or folded to its shortest position, it can't be an AOW. It's not concealable. Too big to easily conceal = "not an AOW" and therefore NO "making an AOW" would happen regardless of what kind of grip you have up front.