The M4 carbine, which was among guns found at businessman Jimmy Wangigi's home on Tuesday, is a shorter and lighter variant of the M16A2 assault rifle.
According to Wikipedia, the M4 is a 5.56×45mm NATO, air-cooled, direct impingement gas-operated, magazine-fed carbine.
The riffle has a 14.5 in (370 mm) barrel and a telescoping stock and costs on average Sh72, 394.
It has the capacity to fire between 700-950 rounds per minute within a 500-metre firing range.
The gun is extensively used by the United States Armed Forces and is largely replacing the M16 rifle in United States Army and United States Marine Corps.
The M4 is also capable of mounting the M203 and M320 grenade launchers.
The distinctive step in its barrel is for mounting the M203 with the standard hardware.
It is also capable of firing in semi-automatic and three-round burst modes (like the M16A2 and M16A4), while the M4A1 is capable of firing in semi-auto and fully automatic modes (like the M16A1 and M16A3).
As a short-range weapon it is quite adequate and thus classed as a submachine gun.
In 1984, Colt began work on a new carbine design called the XM4 combining the best features of the Colt Commando and later the M16A2 rifles.
The first model was designed in 1984 and tested in 1985.
Up to date it is majorly used by the US marines.
The riffle has been widely used in Colombia conflict, Kosovo War, War in Afghanistan, Iraq War and Syrian Civil War.
The M4, along with the M16A4, have mostly replaced the M16A2 in the Army and Marines.
Wikipedia says the US Air Force, for example, has transitioned completely to the M4 for Security Forces squadrons, while other armed personnel retain the M16A2.
The US Navy uses M4A1s for Special Operations and vehicle crews.
Some features of the M4 and M4A1 compared to a full-length M16-series rifle include its compact size, shortened barrel 14.5 in (370 mm), which includes the shorter carbine gas system and telescoping buttstock.
Like all the variants of the M16, the M4 and the M4A1 can be fitted with many accessories, such as night vision devices, suppressors, laser pointers, telescopic sights, bipods, either the M203 or M320 grenade launchers, the M26 MASS shotgun, forward hand grips, and anything else compatible with a MIL-STD-1913 Picatinny rail.
Other common accessories include the AN/PEQ-2 and AN/PEQ-15 multi-mode laser and light modules, Advanced Combat Optical Gunsight (ACOG), and M68 CCO. EOTech holographic weapon sights are part of the SOPMOD II package. Visible and IR (infrared) lights of various manufacturers are also commonly attached using various mounting methods.
"As with all versions of the M16, the M4 accepts a blank-firing attachment (BFA) for training purposes," quotes Wikipedia.
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