My Gamo PT-85 was the first pellet pistol I bought that has a functioning blowback action. While the trigger advances the rotary pellet magazine, the slide cocks the hammer for the next shot. This Gamo PT-85 & the P25 are made in Japan for Gamo, and my guess is that a legendary airsoft gun manufacturer makes these Co2 pistols for Gamo. Alloy lightweight pellets achieve impressive velocities, but I prefer to shoot 7 grain lead pellets, and my own chronograph test results have the muzzle velocity with crosman hollow points around 375 fps, and I usually get around 50 shots per Co2, which is very reasonable considering some gas is used to move the slide, to cock the hammer with each shot fired. The PT-85 is supposedly not a replica of any particular powder burners semi-automatic pistol, but I think it looks loosely based on the Ruger P85, and the P-25 reminds me of the SiG Sauer P-250. Perhaps the model numbers chosen by Gamo are just a coincidence, or a hint to their design influences. I've owned my P-85 since 2014, and with basic care, safe storage, and putting a drop of Pellgun oil on the tip of each co2 cartridge I've charged the gun with, the inner seals and other essential parts are still working as good as the day I bought this co2 pistol.