Military Wiki
Brown Enhanced Automatic Rifle
Type Assault rifle/carbine
Place of origin United States
Production history
Designer Mike Brown
Manufacturer Adcor Defense
Produced 2010–present
Variants BEAR Elite
Cartridge 5.56x45mm NATO
Action Rotating bolt, selective fire
Muzzle velocity 2,800 ft/s (850 m/s) (5.56 mm from a 14.5 in barrel)
Feed system STANAG-compliant magazine

The Brown Enhanced Automatic Rifle (B.E.A.R.) is an assault rifle based on the M16/M4 series. It is produced by the Adcor Defense Company and was one of the contenders in the US Army Individual Carbine Competition to replace the M4 Carbine.


In 2005, Adcor Defense was contracted by Colt to produce upper receivers for the M4 Carbine. Adcor was able to produce 1,000 uppers per day, compared to 450 uppers per day that Colt was able to manufacture.[1] After years of production, designer Mike Brown decided to improve upon the weapon. His end product was the Brown Enhanced Automatic Rifle (B.E.A.R.). He claimed it was not a “new and improved” AR, but a patented revolutionary gas piston system with other key features that set it apart from all other M4-type rifles.[2]


In early 2010, Adcor sent B.E.A.R. rifles to H.P. White Laboratory, known for small arms and ammunition research, development, and testing, to test the reliability of the design. Testing took place from March to April. 6,000 rounds were fired in 120 round cycles, and the guns were lubricated and allowed to cool after 600 round intervals. During the tests, no parts had to be replaced and there were no jams, stoppages, or malfunctions of any kind. Following this, the B.E.A.R. was able to shoot a .88 MOA group at 100 yards with 69-grain match ammo.[3]


On December 8, 2010, Adcor announced production of the BEAR rifle to the civilian market.[4] On June 27, 2011, it was announced that the improved BEAR Elite variant would be available for sale to the public.[5] In June 2012, a soldier was seen in Afghanistan with a BEAR upper receiver with a 10.5 inch barrel on an M4 lower receiver.[6]

Individual Carbine Competition

On May 12, 2011, Adcor announced that its BEAR rifle had been entered in the U.S. Army's Individual Carbine competition. They say their design increases the reliability, accuracy, and lethality of the existing soldier weapon. "The BEAR combines a new piston system with an exclusive ejection port dust wiper with cover, an ambidextrous forward placing charging handle, and a new key-locked, highly rigid rail system."[7] On May 4, 2012, the BEAR Elite version was selected into phase II of the competition.[8][9] The Individual Carbine competition was cancelled before a winning weapon was chosen.[10] On 17 July 2013, Adcor announced it would not protest the Army's decision to terminate the program, and would focus on delivering BEAR rifles to commercial customers. Test results made available to the company said the Army found the B.E.A.R. provided “outstanding” accuracy, even after firing thousands of rounds.[11]

Design details

The cornerstone of the BEAR rifle design is the piston operating system. A gas-driven piston is incorporated into the upper half of the forward rail system and never touches the barrel. This makes the barrel free-floating, which increases accuracy. The operating rod is connected to the bolt carrier group and rides through a machined boss in the receiver rail system interface, keeping the bolt carrier in a linear plane as it operates. This eliminates carrier tilt. A spring-loaded dust shield mounted on the bolt carrier allows the bolt carrier to return to ready position. The port dust wiper moves into the ejection port opening flush of the upper receiver.

A forward placed, foldable, non-reciprocating charging handle is mounted on the handguard, allowing the weapon to be charged or cleared while keeping it pointed toward a target. It is ambidextrous, being able to be removed without tools to either side of the gun. The BEAR has integrated picatinny rails for mounting accessories.[12] The handguard has an M4 profile, so the charging handle is placed directly above the rail. Therefore, it needs a completely unobstructed space on the rail to charge the rifle, negating the usefulness of the rail on the side it is on.[13] By contrast, on weapons like the Adaptive Combat Rifle and the FN SCAR, the charging handle is raised off the side rails, allowing things to be mounted.


BEAR rifles come in barrel lengths of 10.5", 12.5", 14.5", 16", 18", and 20".[14][15]

  • BEAR - Base model. Uses M4-style barrel, A2-style pistol grip, and M4-style stock. Available for civilians in semi-automatic with a 16" barrel.[15]
  • BEAR Elite - Improved version. Incorporates Magpul MOE stock, Magpul pistol grip, and FN heavy barrel used in M249 SAW for longer sustained firing. Available for civilians in semi-automatic with a 16" barrel.[16] This version was entered in the Individual Carbine competition.


  1. Adcor Defense - (0.48-1.10)
  2. Mike Brown - About Adcor Defense
  3. HP White test - Adcor
  4. BEAR available -, December 8, 2010
  5. BEAR Elite available -, June 27, 2011
  6. Soldier Carrying Adcor BEAR Carbine in Afganistan -, June 13, 2012
  7. BEAR enters M4 replacement competition -, May 12, 2011
  8. Phase II selection - Adcor press release
  10. Army Kills Competition to Replace M4 -, 13 June 2013
  11. ADCOR Defense Declines to Protest Army Individual Carbine Decision, Will Focus on Satisfying Commercial Demand -, 17 July 2013
  12. BEAR design -
  13. Charging handle problem -, April 21, 2011
  14. BEAR - Thefirearmblog, January 21, 2011
  15. 15.0 15.1 BEAR -
  16. BEAR Elite -

External links

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