Claremore is about 25 miles from Tulsa on Rt 66, one of the best gun museums in the entire country is in Claremore, the J.M. Davis Gun Museum, it is managed by the state, free admission but donations accepted.  Being the museum itself is owned and run by the state, they are very limited on funds, I really suggest any visitor drop $5 in the donation jar to help with upkeep.  The collection still belongs to the Davis family, the agreement is that the state will furnish the museum to display it, and it is the largest privately owned collection of firearms in the US, although only a part of the collection is on view at any time.  Allow 4 or 5 hours if you can manage it.

JM Davis Gun Museum

The Will Rogers Memorial and Museum is only a couple of miles away.

Will Rogers Memorial