The Caselman Air Powered Submachine Gun

I wonder if this gun is legal to own by anyone since it is not technically a firearm, or if it would come under NFA rules...?

I'd never heard of this gun before, but it turns out that the plans are available from The Home Gunsmith website linked on the right. Instead of lead balls or BB's the gun shoots .311 diameter, 100 gn bullets loaded in a magazine. Power is supplied via an air tank charged at 3,000 PSI.

Apparently, Mr. Caselman disappeared one day and no one has heard from him since...

Part I



Part II