If I researched it correctly, most states will not allow you to own it, and in the few that do, the ATF views any rifle over .50 that doesn't have "legitimate sporting purposes" as being in the same category as a bomb or a missile.

You can still own it in a few states, but you have to fill out a fuck ton of paperwork, wait 18 months at minimum, have a very lengthy background investigation done, get a special license, spend a lot of money on that license and then a shitload more arbitrary taxes the ATF set up to deter people from getting this far, and then hope they don't just decide to deny you anyway.

Basically if you aren't rich as hell, they've de-facto outlawed it.