As long as it doesn't have a threaded barrel. Email LT Hall with the spec sheet and he'll let you know if you can register.
I know what I am good with in DC (and threaded barrels for long guns are GTG), just don't want to make myself an inadvertent felon in MD if I bring the rifle there, as well as I've usually used VA FFLs, but if I use an MD one it has to be legal in both MD (state of sale) and DC (state of residency).