Does this pertain to all pistol braced pistols, such as the Daniels Defense DDM4?
Not yet, but from the ATF letter to Q, it could set a bad precedent to everything using “braces” since the ATF is making, what seems like, an arbitrary ruling.
I personally think that it will all revert back to the original law. Any pistol that has a shoulder stock (by function) will be classed as a rifle, not a pistol.
I sure hope not cause that’s a good amount of money for a new tax stamp and the wait associated with it.