Anybody here been to the NRA Museum in Fairfax, VA?
What a wonderful place. Wonderful history, wonderful guns. Their presentation is a match for any of the Smithsonian buildings in DC.
You do have to get used to having to consult the numerous and easily usable nearby computers for details on the items in the more complex cases, but this way you get more detail than you would from a placard on the exhibit itself.
You could spend hours there. And there's no charge for parking or admission. I highly recommend it.