I came across two interesting machine guns on the web.  The first is a 10/22 Ruger built by Florida Gun Forum contributor Revolverteer into a browning-like receiver with water cooling for the barrel.  It looks to be using a BMF activator to manually crank the semi-auto trigger to crank out the rounds.  Looks like really nice work, and should be a blast to shoot.  And it looks perfectly legal in the US.

picture of home made 10-22 Ruger









The second gun is a dressed up 10/22 Ruger crank fire gun, by Bill Akins.