The Federal legislation proposal coming identifies an assault weapon by one feature as well. Again, pistol grip is all it takes. Also requiring NFA registration, including fees, and all the other BATFE crap that goes with it. Grandfathering to current owner, but no transfer or sale. Once you die, your AR is seized and scrapped.
Might not matter what state you are in, read it and weep:
http://www.feinstein.senate.gov/publ...2-ac8ca4359119