MAC-10

The MAC-10 (Military Armament Corporation Model 10, officially the M-10) is a highly compact, blowback operated machine pistol developed by Gordon B. Ingram in 1964.

Design
The M-10 was built predominantly from steel stampings. A notched cocking handle protrudes from the top of the receiver, and by turning the handle 90° would lock the bolt, and act as an indicator that the weapon is unable to fire. The M-10 has a telescoping bolt, which wraps around the barrel. This allows a more compact weapon, and balances the weight of the weapon over the pistol grip where the magazine is located. The M-10 fires from an open bolt, and in addition, the light weight of the bolt results in a rapid rate of fire. In addition, this design incorporates a built in feed ramp as part of the trigger guard (a new concept at the time) and to save on cost the magazine was recycled from the M3 Grease Gun. The barrel is threaded to accept a suppressor, which worked by reducing the discharge's sound, without attempting to reduce the velocity of the bullet or rather stops air from rushing into the barrel, inhibiting the sonic signature. At the suggestion of the United States Army, it also acted as a foregrip to inhibit muzzle rise when fired. Ingram added a small bracket with a small strap beneath the muzzle to aid in controlling recoil during fully automatic fire.

Suppressor
The primary reason for the original M-10 finding recognition was its revolutionary sound suppressor designed by Mitchell Werbell III of Sionics. This suppressor had a two-stage design, with the first stage being larger than the second, its purpose to house material to baffle air from rushing into the barrel directly. This uniquely shaped suppressor gave the MAC-10 a very distinctive look. It was also very quiet, to the point that the bolt could be heard cycling, along with the suppressed report of the weapon's discharge; however, only if subsonic rounds were used. The suppressor also created a place to hold the weapon; this, combined with the weight it added, made the weapon easier to control. During the 1970s the United States placed restrictions on the exportation of suppressors, and a number of countries canceled their orders of M-10s as the effectiveness of the MAC-10's suppressor was one of its main selling points. This was one factor that led to the bankruptcy of Military Armament Corporation, another being the company's failure to recognize the private market. The original Sionics suppressor is 11.44 inches in length, 2.13 inches in overall diameter, and weighs 1.20 pounds.

Nomenclature
The term "MAC-10" is commonly used, but unofficial parlance. Military Armament Corporation never used the nomenclature MAC-10 on any of its catalogs or sales literature, but because "MAC-10" became so frequently used by Title II dealers, gun writers, and collectors, it is now used more frequently than "M10" to identify the gun.

Calibers and variants
While the original M-10 was available chambered for either .45 ACP or 9mm, the M-10 is part of a series of machine pistols, the others being: the MAC-11 / M-11A1 semi, which is a scaled down version of the M-10 chambered in .380 ACP; and the M-11/9, which is a modified version of the M-11 with a longer receiver chambered in 9mm, later made by SWD (Sylvia and Wayne Daniel) and Leinad.

In the United States, full automatic M-10 machineguns are NFA articles. As Military Armament Corporation was in bankruptcy large number of incomplete sheet metal frame flats were given serial numbers then bought by a new company, RPB industries. Some of the previously completed guns (already stamped MAC), were stamped on the other side RPB thus making it a double stamp gun. RPB Industries made many open bolt semi guns and sub machineguns before the ATF seized roughly 200 open bolt semi autos in use in the drug wars of 1981. The company did not recover from this decision. Wayne Daniel then a machine operator for them purchased a lot of their remaining inventory and formed SWD, designing a new weapon which was more balanced, available fully automatic or semi-automatic with his new ATF approved closed bolt design. This design is still present today.

The original rate of fire for the M-10 in .45 is 950 rpm. That of the M11/nine 9mm is 1150 rpm, and that of the M11 .380 is 1380 rpm.

Lage Manufacturing is making a very popular variant, which are called "MAX" uppers. The company is based in Chandler, Arizona. The "MAX" upper can reduce the original rate of fire to about 600 RPM (.45 ACP) and 700 RPM (9x19mm). The upper adds a picatinny optic rail, a side cocking charging handle, and a forend.

Lage Manufacturing is currently marketing a drop-in .22LR caliber conversion upper variant for the M11-A and Max-11.

Alliance Armament is making slowfire uppers that accept unmodified Suomi 36 round stick magazines, 50 round coffin mags, and 71 round drum magazines. They are also producing a 7.62x25 PPSh-41 compatible conversion for the upper, which based on the low cost and high power of the round, should become very popular, especially with subgun competitors.

Besides Military Armament Corporation, MAC-10s and MAC-10 parts have been produced by RPB Industries as well as complete guns. Another company was Leatherwood Texas MAC, Cobray Company/SWD/Leinad, Jersey Arms Works, MasterPiece Arms, Section Five Firearms and Vulcan (Velocity Arms, V-series).

1994 Assault Weapons Ban
Possibly due to its menacing appearance and the reputation the open-bolt version gathered before the 1982 open-bolt ban, the semi-auto civilian version of the MAC-10, which operates differently than its military counterpart, became a target of the 1994 Assault Weapons Ban. The ban enacted various requirements which defined an assault weapon. Not only was the MAC-10 named directly in the ban, it also failed two of the requirements: 1. A semi-auto version of an automatic firearm. And 2: A manufactured weight of 50 ounces or more when the pistol is unloaded. The imposed weight limit was 50oz (1.4 kg), which the MAC-10 exceeded with its weight of 100.16oz (2.84 kg). More importantly there were two other fundamental problems: The weapon contained a threaded barrel which added the ability to attach a suppressor, and the magazine capacity was thirty two rounds, well exceeding the limits of the ban. In response, Wayne Daniel redesigned the weapon to no longer accept the suppressor, and created a new magazine release that would only allow ten round magazines as the 1994 Assault Weapons Ban mandated. The new weapon was called the PM11/9.

BXP
The BXP is 9 mm submachine gun developed in the mid-1980s by the South African company Mechem (currently a division of Denel, formerly under ARMSCOR) and brought into production in 1984. Due to international arms embargoes of Apartheid South Africa, the country was forced to design and manufacture their own weapons. The weapon was intended for use by security forces. The manufacturing rights shifted from hand to hand several times during the years, passing from Mechem to Milkor Marketing and later to Truvelo Armoury, the current manufacturer (as for 2009).

Cobra submachine gun
The Cobra Land Defense Pistol is a semi-automatic stocked pistol of Rhodesian origin manufactured during the Bush War Era as a 'Land Defence Pistol' for farmers and is chambered in the 9mm round. The layout of this weapon is somewhat based on the Uzi submachine gun.

Patria submachine gun
The Pistola Ametralladora Patria is a close copy of the MAC-10 and features a cooling jacket/barrel extension much like the South African BXP. The P.TO. country was developed for the major of the Air Force Argentina, Luis Ricardo Dávila, and protected by national Patent n° 220494/5/6/7 on 20/08/1980. It uses 9mm caliber rounds for easy transportation, and can be operated in either hand.

Enarm SMG
The Enarm MSM/SMG was a submachine gun of Brazilian origin based on the Uzi and MAC-10 weapons. It was chambered in the 9x19mm Parabellum round and also came with a foregrip. Although the weapon performed well in trials, it was discontinued due to financial reasons.

Users

 * 🇦🇷 Argentina
 * 🇧🇴 Bolivia
 * 🇨🇱 Chile
 * 🇩🇴 Dominican Republic
 * 🇬🇷 Greece
 * 🇬🇹 Guatemala
 * 🇭🇳 Honduras
 * 🇮🇱 Israel
 * 🇵🇱 Poland
 * 🇵🇹 Portugal
 * 🇸🇦 Saudi Arabia
 * 🇪🇸 Spain: Used by various police forces.
 * 🇬🇧 United Kingdom Used by the SAS.
 * 🇺🇸 United States: Used by special forces, including LRRPs and Navy SEALs, in the Vietnam War.
 * 🇺🇾 Uruguay
 * 🇻🇪 Venezuela