The M7 bayonet is a bayonet that was used by the U.S. military for the M16 rifle, it can also be used with the M4A1 carbine, Steyr AUG and the IMI Galil assault rifles and carbines, and Mossberg combat shotguns. It can be used as a fighting knife and utility tool. It was introduced in 1964, when the M16 entered service during the Vietnam War.
The M7 is based on the older M6 bayonet for the M14 rifle. The most notable differences between the two are the diameter of the muzzle rings, and the locking mechanism. The M7's release mechanism is on the pommel, while the M6 has a spring-loaded lever near the guard that when depressed releases the bayonet. Both models are approximately the same length, have the same black finish, and use the M8A1, or later M10 sheath.
The M7 blade and hilt are very similar to the M4 bayonet with the Korean War era plastic grips for the M1/M2 carbines except that the M7 has a much larger muzzle ring. The M7 has the same two-lever locking mechanism as the M4, that connects to a lug on the M16 barrel. The blade and basic grip for the M7 is similar to the M6 (M14 rifle), M5 (M1 rifle), and M4 (M1/M2 carbine), all derived from the World War II M3 fighting knife.
The M7 1095 carbon steel blade is 6 3/4 inches long, with an overall length of 11.9 inches. Blade width is 7/8 inch and it weighs about 9.6 ounces. One edge is sharpened its full length while to opposite side of the blade has approximately 3 inches sharpened. There are no markings on the blade itself. The manufacturer's initials or name along with "US M7" will be found stamped under the crossguard (see photo, right). The non-slip grips are molded black plastic. The steel parts have a uniform dark grey/black parkerized finish.
The M7 bayonet NSN is NSN 1005-00-017-9701. The initial contractor was Bauer Ord Company. Colt (manufacturer of the M16) and Ontario Knife Company made many of the M7 bayonets for the military and continue to make and sell them commercially. Other manufacturers included Carl Eickhorn [for Colt], Columbus Milpar & Mfg. (MIL-PAR), Conetta Mfg., Frazier Mfg., General Cutlery (GEN CUT), and Imperial Knife. About 3 million M7 bayonets were delivered.