You may own automatic weapons by going through (I'll be nice!) the BATFE and filling out the forms, crossing all the T's and Dotting all the I's and fingerprint cards and $200 for a tax stamp. Other than ALL THAT, yes IF you are approved. Guys, correct me if I'm wrong! LOL!
I really don't see the big deal anymore with all of the FRT and SS trigger assemblies you can get in a 8" AR15 chambered in whatever caliber you want. Anything from 50 beowulf to 22LR