Cybergun - Magnum Research - Semi-Auto - Desert Eagle L6- CO2 Blowback. 177 Steel BB Air Gun -New! Realistic blowback action provides a healthy kick and an impressive display of performance. Developed in the late 1970's / early 1980's, Magnum Research and Israel Military Industries (IMI) wanted to venture into the magnum side arm market that was mostly dominated by revolver style weapons.