MAC-11

The Ingram MAC-11 (Military Armament Corporation Model 11 Advancement 1 or M11A1) is a machine pistol designed by Gordon Ingram at the Military Armament Corporation (MAC) during the 1970s. The weapon is a sub-compact version of the Model 10 (MAC-10), and is chambered to fire a smaller .380 ACP round. This weapon is sometimes confused with the Sylvia & Wayne Daniels M-11/9 or the Vulcan M-11-9, both of which are chambered for 9 mm Para. The M11/9 was made after the M11A1 and is seen by many to be a copy with upgrades. Like the larger M-10, the M-11 has open sights with the rear pinhole sight welded to the receiver. These sights are for use with the folding stock, as using them without the stock is nearly useless because of the initial jump of the weapon due to its heavy, open-bolt design. The M-11A1 also has two safety features which are also found on the Model 10A1. The charging handle rotates to the 90 degrees to lock the bolt in the forward position thus preventing the weapon from being cocked. The second safety is a slider which is pushed forward to lock the trigger, which in turn pins the bolt to the rear (cocked) position. This prevents the weapon from discharging even when dropped, which is a typical problem with the open-bolt design.

Sound suppressors for the M-11A1
The M-11A1's suppressor uses wipes instead of the reflex type that Mitchell Werbell III created for the M-10. Though this type does not last as long as the reflex suppressor, it proved to be exceptionally quiet. At one point, a special briefcase was made that could hold an M-11 with its suppressor attached, similar to the famed HK PDW case. The gun could be fired from inside the briefcase by pushing a button. A business card was cleverly placed over the hole where the bullets exited, totally disguising it. This case was intended for use by VIP protection, and needs to be registered with BATF; the case is considered to be an "Any other weapon" if used in conjunction with a semi automatic firearm which requires separate registration in addition to the gun and its suppressor.

Performance
The rate of fire of the M-11A1 is listed in most manuals as approximately 1200 rpm (rounds per minute), though in reality, it is closer to 1600 rpm. Like most automatic weapons, the cyclic rate is sensitive to variables like the loading of the ammunition and the thickness of the recoil buffer. At this incredibly high rate of fire, the weapon is difficult to control while on full-auto, but quick bursts can cause devastating results at ranges up to about 30 yd. Because of the low penetration of the .380 ACP round, the M-11A1 has found uses in situations where a more powerful round could pass though a wall and inflict collateral damage. The M-11A1 has found uses with some security forces, and most special task forces around the world have used them during in-vehicle operations such as an airliner because of the low penetration of the .380 round.

Limited success
The M-11A1 is the least common version in the MAC family of firearms. This is mostly due to the .380 ACP round (approximately 950 ft/s and has 200 ft.lbf of energy), which is widely considered to have insufficient stopping power. At 1600 rounds per minute, extreme trigger discipline is required to discharge short bursts, which are required for this weapon to be combat effective. Without proper training, the natural tendency of the inexperienced shooter is to hold down the trigger, which discharges the entire capacity of the magazine. Because of this high rate of fire, it has found limited uses, but still remains in worldwide use.

Manufacturers
MAC-type pistols were first manufactured by the Military Armament Corporation, and later by RPB Inc., Sylvia/Wayne Daniel Inc., Cobray, Jersey Arms, Leinad, MasterPiece Arms, and Vulcan. Modern manufacturers include:


 * 1) Cobray currently manufactures the required parts which are assembled into functional firearms by Leinad (Daniel spelled backwards). Leinad, because it assembles the MAC-10, is legally considered the manufacturer.
 * 2) MasterPiece Arms currently manufacturers possibly the highest quality line of "MACs" ever built, utilizing several of their own small design improvements like a non-spinning bolt handle and a redesigned bolt.
 * 3) Vulcan Arms makes a full line of "MACs."  Vulcan appears to have borrowed a few improvement ideas from MasterPiece Arms, but not all.  Their .45 has a non-spinning bolt handle, but not their 9 mm.  Vulcan uses a hex bolt to secure the upper receiver to the lower receiver, which is unusual.  Vulcan's "MAC" carbines are definitely unique in their design and appearance.