Where do you shoot them at? A few of my local ranges have signs up stating no machineguns.
I have been to a range in wilkes county and when I started shooting people cleared out like WWIII had just started....I dont know if they thought I was the law or that I may attract the law.

Yes,
I have a full auto MAC/10 and a Stemple MKIII 45/76. I also have a silencer on a Browning Buckmark and a silencer on an AR-15. Most D.N.R ranges in S.C. are full auto friendly.
When I first started bringing them to the range I was kinda paranoid ( I felt kinda like I was doing something shady) but now I don't think twice about it. As long as you got your paperwork don't sweat it. One time I got almost to the range (about 40 minute drive) and realized that I forgot my drivers license and went all the way back home to get it just in case the man showed up. So far in the past year, I've never been asked to show my papers.
With each trip to the range I almost always let at least 1 person I meet have a free mag on the house with his gun of choice. Hopefully I'll spread the fever.
Have fun,
Base-Rigger

What region of NC are you in?  I don't own anything NFA  (but I will.... Oh but I will... ).  However, I do know of a range (Frank's in Oxford) where it's welcome and encouraged.  It's a private range, and mainly caters to the weekly IDPA/three gun matches, however he does sell very inexpensive memberships to people who he knows, trusts, and likes.  I believe it's OK at Sir Walter, but Frank's in Oxford is definitely NFA OK.  

I live in the Iredell/Rowan area.
I shoot on a friends land at present but would like to find a place to shoot where I can meet other shooters and not have to rely on my friend to be in the mood to shoot.