The M933P is a carbine variant of the M16A5P, styled and named after the Model 933 “M4 Commando” carbine. It was adopted to fill the need for a compact version of the M16A5P for use in close-quarters combat. Coming into service in 2034, the M933P was adopted by all the militaries that used the parent M16A5P rifle. It is used by vehicle crews and support personnel, such as mortar crews, but sometimes entire units will issue the M933P to regular troops for close-quarters combat. Over time, it has been replaced largely replaced by the M41 and later the M39 submachine guns, but remains in use for certain roles, particularly for large-unit issue.
|Weapon Designation:||Carbine, 5.6mm, Pulse-Fired, M933P|
|Place of Origin:||United States|
|Manufacturer:||Colt Arms Manufacturing|
|Weight:||4.5 lb (2.05 kg)|
|Length:||31 in (787 mm) (stock open)|
27 in (686 mm) (stock closed)
|Barrel Length:||11.5 in (292 mm)|
|Action:||Gas-operated direct impingement, electronically ignited cartridges|
|Rate of Fire:||700 rounds/min cyclic|
|Muzzle Velocity:||2,882 ft/s (878 m/s) with M5-662 round|
|Muzzle Energy:||1,144 ft/lbs (1,551 Joules) with M5-662 round|
|Effective Range:||400 m (273 yd)|
|Feed System:||30-round detachable box magazine|
|Sights:||Iron sights or M76 CQO red dot sight|
Although the M41 pulse rifle was considered satisfactory for close-quarters combat, its caseless ammunition was the cause of several issues, primarily rapid overheating of the rifle, along with the ammunition itself being somewhat fragile and highly sensitive to contamination by foreign substances. A more durable firearm using cased ammunition was desired for more versatile situations, which led to the creation of a carbine variant of the existing and highly satisfactory M16A5P. This carbine, the M933P, uses all of the technology and advancements of the M16A5P, but features a short barrel and handguard, as well as a flat-top upper receiver with a rail mount. The introduction of the M39 submachine gun fixed a number of the M41’s problems and some users who had switched from the M41 to the M933P ended up carrying a submachine gun again in the form of the M39. The M933P was most commonly used by personnel who wanted or needed a compact firearm with an effective range of over 200-250 meters.
The M933P is nothing more than an M16A5P with a flattop upper receiver and a shorter barrel, handguard, and gas tube. Although it can be used with the fixed stock, M933Ps are almost exclusively found fitted with the collapsible stock. The 11.5-inch barrel features the same 1:9 rifling as found in the M16A5P’s 20-inch barrel, and the carry handle and sight set-up are the same. The flattop receiver is usually used to mount either a standard carry-handle or an M76 Close-Quarters Optic red dot sight.
Range, Accuracy, and Terminal Ballistics:
The shorter barrel of the M933P greatly reduces the carbine’s effective range from 800 meters for the M16A5P to just 400 meters for the M933P. Within that range, the accuracy and terminal effects of the M5-662 round is virtually unchanged from the M16A5P, but at greater ranges, accuracy and terminal effectiveness begin to drop off rapidly. Despite this, it remains a highly effective and reliable weapon under all battlefield conditions and it is greatly respected by the troops who carry it.
The M933P cannot mount a bayonet, although it does have several under-barrel weapon options, the first being the M23A1 40mm grenade launcher. More common, however, is the 30mm pump-action U1A1 grenade launcher, a variant of the U1 grenade launcher modified to fit the M933P, while a third option is the U7A1 under-barrel shotgun.
To rectify the issue of not being able to mount a bayonet directly, a new bayonet designated the M32 was designed with a different mount that clamps to the barrel under the front sight post, although this requires that a different front sight post with no bayonet lug be used. The clamp mount replaces the bayonet lug, making sure that the bayonet does not slide forwards or backwards along the barrel.