1-18 takes a good look at the USHOT M40 gas-powered shell-ejecting airsoft rifle, which is based on the classic sniper rifle used by the U.S. Marine Corps. He explains that while the M40 series eventually evolved into more modern configurations with synthetic stocks and advanced rails, this specific model captures the early retro charm of the Vietnam War era.

UShot gives a quick look of the features of the Maruyama ISO 556 GBBR.