By David Crane
defrev at gmail dot com
All of the photos contained in this article, with the exception of the first/top photo, were taken by Chen Lee a.k.a. "SMGLee" at the 2008 AUSA Annual Meeting and Exhibition, and he owns the copyright on these photos. Colt Defense, LLC provided the first/top photo.
October 20, 2008
While I was visiting Colt headquarters last month, I got the chance to handle the Colt IAR (Colt Infantry Automatic Rifle) candidate. The Colt IAR is chambered for the 5.56x45mm NATO (5.56mm NATO)/.223 Rem. round and is designed to "satisfy the role currently played by the FN M249 SAW in a lighter, more man-portable mode" (Colt’s words) at significant cost savings vs. the SAW.
Interestingly, the Colt IAR operates via…
direct gas impingement, not gas piston/op-rod. Colt went with the direct gas impingement system because “there was no improvements to the reliability of the weapon when properly maintained, and the overall weight was lower with the gas impingement system,” according to Phil Hinckley, Executive Director of Quality and Engineering at Colt Defense LLC.
The Colt IAR utilizes a monolithic upper receiver that incorporates a Mil-Std-1913 "Picatinny" quad rail system/forend rail tube which contains a rather large heat sink to prevent cook-offs.
DefenseReview has been informed that Colt IAR doesn’t utilize Colt’s proprietary and patent-pending Gas Regulator Sleeve a.k.a. Gas Impingement Sleeve, which was designed to control the cyclic rate/ROF over the life cycle of the weapon. However, Mr. Hinckley informed us that Colt Defense may add this feature on a future revision of the weapon.
Due to the large heat-sink component situated under the barrel, the Colt IAR is somewhat front-heavy a.k.a. muzzle-heavy. This, along with its 9.5-lb overall (OA) weight should significantly reduce barrel rise (a.k.a. muzzle flip) while firing on full-auto, even at the IAR’s 700-1000 rpm cyclic rate/ROF.
Mr. Hinckley informed Defense Review that the Colt IAR “has been tested by the military, it is our understanding that the testing is still on-going and a final selection has not taken place.”
Caliber: 5.56×45 NATO (5.56mm NATO)/.223 Rem.
Empty Weight (Dry Weight): 9.5 lbs
Extended Length: 36.75 inches (36.75")
Collapsed Length: 33.50 inches (33.50")
Folded Length: Not Available (NA)
Barrel Length: 16 inches (16")
Bore: Chrome-Lined, 6 Grooves, 1:7" twist, Right-Hand (RH) Twist
Method of Operation: Direct Gas Impingement with Locking Bolt
Muzzle Velocity: 2900 fps
Effective Range: 600 Meters (600M)
Front Sight: Adjustable Folding Front a.k.a. Adjustable Flip-Up/BUIS
Cyclic Rate of Fire (ROF): 700-1000 rpm
Fire Control: Safe, Semi-Auto, Full-Auto
Upper Receiver: Flat Top, Monolithic Upper Receiver
Photo Credit: Colt Defense LLC and Chen Lee a.k.a. "SMGLee"
Colt Defense LLC
547 New Park Ave
West Hartford, CT, 06110
800-241-2485 Toll Free
Acronyms and Abbreviations used in this article:
ROF – Rate of Fire
Op-Rod – Operating Rod
Full-Auto – Fully-Automatic
BUIS – Back-Up Iron Sight
SAW – Squad Automatic Weapon