DFX TECHNOLOGY
M4 / M203
The Colt company has developed various carbine versions of the basic AR-15 / M16 rifle since the 1970s. These carbines were intended for all markets - military, law enforcement, civilian. The US Military (and some other armies, most notably - Israeli Self-Defense Forces) had adopted the Colt CAR-15 Commando and XM-177 carbines during the 1970s and 1980s. In 1994, the US Army adopted the Colt Model 720 selective-fire carbine (basically, a shortened M16A2 rifle), as the US M4 Carbine. This weapon was intended to replace in service some M9 pistols, as well as some aged M3A1 submachine guns and some M16A2 rifles. The new weapon was much more handy and comfortable to carry, than the long M16A2 rifle, so the US Special Operations Command (SOCOM) put its eye on the M4 as a possible universal weapon for all Special Operations community. For this purpose M4 was latter modified with the M16A3-style flat-top receiver with integral Picatinny-type accessory rail instead of the M16A2/M4-type integral carrying handle. The other change in the M4A1, when compared to M4, is that its trigger unit is modified to fire full-auto instead of the three shots bursts. Specially for the SOCOM M4A1s US Naval Surface Warfare Center developed a SOPMOD M4 kit, that consisted of the M4A1 carbine equipped with Rail Interface System (RIS) instead of the standard handguards. The kit also includes a variety of the add-on goodies, such as various sights (ACOG 4X telescopic, ACOG Reflex red-dot, detachable back-up open sights), laser pointers (visible and infra-red), detachable sound suppressor (silencer), modified M203 40mm grenade launcher (with shortened barrel and improved sights). The kit also included a detachable front grip and tactical light.

The M4 carbine differs from the M16A2 rifle only by having a shorter barrel and a telescoped, 4-position buttstock. The M4A1 is a similar modification of the M16A3 rifle.

The M203 grenade launcher was developed between 1967 and 1968 by the AAI Corporation of USA. Since AAI had no resources for mass production, the manufacturing contract was issued to Colt. Later on, more or less exact copies of the M203 were produced in Egypt, South Korea and Bulgaria (as UBGL-M1, with mount suitable for Kalashnikov AKM and AK-74 type rifles). During the 1990s, M203 went into several modifications, such as shorter-barreled M203A2, intended for shorter M4 carbines used by US SOCOM. M203 launchers are still being used by US armed forces, and by many other armies, including those of Australia, Israel, South Korea, Philippines, Turkey and some others.

The M203 is a single-shot, breech-loading weapon with rifled barrel. The rear part of the barrel is covered with a polymer handgrip. If necessary, the M203 can be mounted on separate shoulder-stock / pistol grip assemblies (available from several companies, such as Colt or Knight's Armament) to be used as a stand-alone weapon.