It depends on the state, but generally its ok. From another post of mine where I build a Para and I'm in Kali.
I built a home grown Para quite some time ago. Numbers all match, in the white mostly.
It came to me cut, and this is what I did with it. After facing the muzzle & adding an 11* target crown and a short TriDelta 14X1 LH brake, I put on a Prince 50 front sight, and a Williams Fire sight (with the aperture removed, they're like ghost rings, very fast acquisition). It works perfect for my poor vision in my good eye. I've had it in Tapco T6, Choate Drag, and in Butler Creek/K-Sport furniture. I've posted it before, but it's currently as pictured with black web sling. PAX