I have a 7.5" in 300 Blk I built. No hand stop, but it does have flip ups and a Sightmark M-Spec reflex (which works easily at arms length, like a pistol), I also have the SBA-3 brace and apparently, THAT'S what the ruckus is about. In addition, check that sheet closer too as length of pull matters, weight matters and over all length matters as well.
I'm still trying to find out if that new sheet and the proposed rule changes are actually in effect yet. The ATF's site is convoluted as heck and there is no straight answer. As of today (the 8th) I'm 13 months into my wait for my form 4 tax stamp on a suppressor I bought last year (which I intend to use on ther 300 Blk pistol). I called thge ATF last week and was told it is still "pending." I'm a bit miffed because it looks like I won't be able to enjoy my pistol with the suppressor as I wanted...back when I jumped through all the hoops to ensure I was building a legal pistol.
Since form 4's went electronic this past December, I think they pulled half (or more) of the few people they have working paper forms to deal with the electronic side and so now there are even less people working on the paper forms. I know a few folks who purchased suppressors using the new electronic method in January and February of this year and they already have their stamps and suppressors in hand. Grrrrrrrrrrrrrrrrrrrrrrrr.....
When/if the new rules by these unelected rogues go into effect, then I have 3 choices: Shut my pie hole and leave it as it is (and never take it to the range), take off the brace, change the tube (so it's not "adjustable") and take off the flip ups, or spend another $200 and form 1 it as an SBR.
I'm leaning to the latter. Yeah, sucks to have spend another $200 and get "permission from the man" to exercise my rights, but an SBR means I can put an actual stock on it, vertical grips, or anything I want (I can even buy more uppers for it and shoot whatever caliber I want) without having to play whack-a-mole with the moving goal posts of "rules." Many lament doing that as it does put restrictions on toting it around or crossing state lines, but I rarely go out of state, and have no reason to take it with me if I do.
Here's my pistol: