Grease Gun M3 and M3A1 9mm Auto Barrel with Trunnion. This is a new 8" barrel for the famous M3 or M3A1 Grease Gun. Made from high grade tool steel and chambered in 9mm Luger. Ready to screw in and shoot! In the white. This is threaded for an original military firearm and will not fit the Valkyrie Arms semi auto. Note: you will need one of our 9mm bolts (M3Bolt9 or M3A1Bolt9) and Sten magazine adapter (GGADPT) in order to use.