This is a miniature paper model of the Browning .50 caliber machinegun. It is a total of 8" long and yes... those are .22 LR shells in the chain. Makes a nice touch. I am going to mount it on my scale remote control Jeep Willy.
This is a preliminary concept prototype #1. I have since modified it and have sold many to scale modelers who needed artillery on their RC vehicles (I guess the idea caught on)... *whew* good thing 22LR-ammo is cheap at the range!