garyfo,
Last year a couple friends and I took a trip to the IPMS NATS in Virginia Beach. We took the opportunity to make a week of it and stopped at a buncha places on the way, DC being one of these.
We had absolutely no problem whatsoever. No lines, just security changes, according to my pal Goon. Wands, bag & purse scans and all that.
'Twas my first visit to this place, and it certainly won't be my last. I've wnted to see that Ferris mural of T-Bird since I was about 12, was pleasantly surprised that they had an exhibit (Temporary, I think) on the Soviet space program and I even got to see a piece of my Dad's handiwork!
I was surprised, however at the layout of the place. I had envisioned a bit more wide open space. And that's not a complaint, I was just surprised that it was that much different from what I had imagined.
Anyhoo, I doubt you'll have much trouble getting in. Then again...
Fade to Black...