In this final episode of "cool stuff" from the NRA Museums, John Popp and firearms specialist Logan Metesh are sitting at a typewriter. It's the Chicago Typewriter, the iconic Thompson model 1921 submachine gun, the Tommy Gun. You've seen it in the hands of gangsters, law enforcement and the military, but this gun's special. It's serial number 1435. Its 100-round drum magazine is also serial number 1435. It's rare to find a Tommy Gun with the original mag serial numbered to the gun. See it in the new "Thompsons by the Dozen" exhibit at the NRA National Firearms Museum in Fairfax, Virginia.