The MAC-10 (Military Armament Corporation Model 10) is a highly compact, blowback operated, selective fire submachine gun (technically, a machine pistol) developed by Gordon B. Ingram in 1964.
The MAC-10 is a low cost, simple design with with relatively few moving parts, making it simple to maintain and manufacture. The M-10 is the first out of a family of machine pistols, the others include the Mac-11 (M-11A1), which is a stripped down variant of the M-10 chambered in .380 ACP; and the M-11/9, which is a much smaller 9mm variant that has a shorter profile adn longer receiver later made by the Leinad (Daniel backwards), Cobray (cobra+moray) and the SWD (Sylvia and Wayne Daniel companies.
The high rates of fire and compactness for these submachine pistols (generally not less than 1000 rpm for the M-10 and generally not less than 1600 rpm for the M-11A1) worked against them. The MAC-10's diminutive size made them fairly difficult to hold. The difficulty to be held when combined with their extremely high rate of fire (the magazine can be emptied in 1.57 seconds on full auto), made control of the sub machine pistol challenging. The two aforementioned facts were the key reasons that the pistol was not adopted by the military. Also, their overall weight makes them uncomfortable for most to hold. Despite its limitations, the MAC-10 was used in limited service in Vietnam with the Special Forces. The MAC-10 is still in some general use today by certain units in the U.S. Army, some SWAT forces, the Brazilian Army's elite counter terrorist special forces, and security outfits. The extremely high rate of fire, regardless of the difficulty when controlling the recoil makes the MAC-10 useful in certain situations.
Chambered in the .45 ACP rounds, the MAC-10 is the most common submachine gun. Within the United States, a MAC-10 that is fully automatic is a NFA articles and one of the least expensive and more common fully automatic weapons on the US market. The MAC-10 pistol may be simply converted to carbines and back to the regular version by interchanging frequently available parts of the weapon. When Ingram first made the MAC-10 into a .45 caliber weapon he had this idea. The ultimate fabrication and design of the first MAC-10 firearm was done by Erquiaga Arms in 1962 of Southern California.
The MAC-10 enjoyed enormous success because of a suppressor designed by Mitchell Werbell III of Sionics. The suppressor was revolutionary and had a atwo stage design. The first stage of the suppressor was larger than the second. The shape of the suppressor was unique and gave the MAC-10 a very intimidating look. The MAC-10 was very quiet when using the suppressor. It was so quiet that the bolt could be heard louder than the weapon being fired. An additional place to hold the weapon was also created by the suppressor and with its increased weight made the firearm much easier to control. The firearm's barrel threads were initially intended for this suppressor, however many other attachments may be used: fake suppressors, muzzle brakes, fore grips, barrel extensions and more. Interestingly, enough, the First Stage Suppressor is considerably larger than the gun itself.
Current military users
The present use of the MAC-10 among military users is for counter-terrorist units throughout the world. The weapon's high rate of fire and generally low power is found to be ideal in hostage situations.