Special Operations.Com

Today the M-4 Carbine has achieved a unique status, it is used by every service branch in the United States and has sold to numerous other countries across the globe.  Yet many people labor under the belief that it is a new CAR-15 model, the purpose of this article is to detail the origins of the M-4 Carbine, it's evolution, variations and accessories.

Experiments to create a lightweight and handy carbine based on the M-16A1 go back to 1965 when engineers at Colt began to tackle this problem, the first prototypes were designated the XM177E1 (Model 609, 610 & 610B).  The Model 609 was sent to the US Army for field trials, the Models 610 & 610B were shipped to the US Air Force to test.  The Model 609 and 610 weapons were both created to fire single shot or full-automatic, however in a ironic hint of the future the Model 610B had a three round burst limiter.  The only downside which arose with the carbines was the short 10 inch barrel, the weapon showed some problems with ammunition.  The problems caused by switching to stick powder caused frequent jamming incidents-this gave the M-16 family in general a bad reputation.  This problem was aggravated by the fact that the M-16/CAR-15 series of weapons when fired on full automatic caused excessive carbon build up inside the barrel.  This was truly problematic in that the weapons had been advertised to the soldiers in the field as not needing cleaning, as proof of this there were no cleaning kits issued to the soldiers.  To remedy this the barrels of the weapons were chrome plated, this made it easier for cleaning rods to remove excess builds up.  In addition firearms cleaning kits were hurriedly rushed in country for the soldiers.  A Congressional inquiry was held to get to the root of the matter, it was determined that the change to stick powder was the culprit-the policy of using stick powder was dropped afterwards.

However with the XM177E1 there was an additional problem which was encountered as well, they didn't adjust the size of the gas port on the 10' barrel which resulted in sporadic operation.  To correct this problem the barrel was lengthened to 11.50 inches overall, the E1 Models were replaced by the XM177E2 variants (also known as the CAR-15 or "Shorty 16").  Both weapons were fitted with a flash suppressor on the end of the barrel, testing had shown that the weapons had a excessive muzzle flash which was QUITE visible during night time operations.  The result was an extremely popular weapon, due to it's length it was popular with dog handler units and officers.  The popularity of the weapon did have a negative effect though for some elite units which had difficulty in acquiring the weapons for use.  Once they did acquire the weapons they often held onto them for dear life.

"The other major limitation of the rifle was one the LRRPs could not control.  The CAR-15 was extremely popular with staff officers and other rear-echelon types who liked to look like the warriors they so avoided joining.  As a result, the CAR-15s were always in short supply, and the ones that were available were passed along from replacement to replacement.  Many LRRPs who served in the final years of the war recall carrying nearly worn-out weapons with barrels so used that much of their accuracy had been lost."  (Lanning: Inside The LRRPS, Page: 124)
 

 
 

The Heir To The CAR-15

The Colt Commando (sometimes referred to as the M-16A2 Commando)  represents a modern CAR-15 design, it was created for Special Operations Personnel and or Government Agencies who needed a concealable but potent weapon.  Designed in early --- the Commando is noticeably different from it's predecessor in the fact that it does not use a suppressor to mask it's muzzle flash.  It is instead fitted with an A2 Model flash hider/compensator, this change does help the user control the climb of the weapon when fired but does little to reduce the large muzzle blast.