http://www.forgottenweapons.com http://www.gunlab.net This particular rifle is a prototype of the reproduction VG1-5 (or more correctly called the Gustloff MP-507) rifles that will be available for sale soon from Chuck at GunLab.net. The VG1-5 was a gas-delayed blowback design that has been used in handguns, but not in any other rifle designs. For more details on the gun, check out my full video on it here: https://www.youtube.com/watch?v=anW7HWFlueg