BCM MK2 300 BLK Upper Receiver Group

Overview It’s no secret that we’re particularly fond of BCM’s MK2 lineup. These MK2 300 Blackout uppers are great suppressor hosts as they feature a continuous-taper profile barrel that keeps the weight back towards the receiver and makes the front light and maneuverable. Pair this with the enhanced MK2 upper receiver, which gives you a relocated forward assist and unmatched rigidity, and you have an accurate and consistent foundation that will be ready to perform for years to come. Lastly, an often skipped-over feature is BCM’s thermal fit tolerances on both the handguard and barrel extension. This provides superior fit and finish and increases service life and overall consistency. What’s Included 1x BCM Upper Receiver with BCG 1x M-LOK Picatinny section 1x BCM M-LOK QD mount Specs FEATURES Warranty: Covered by BCM’s manufacturer warranty. Warranty service is provided by BCM. UPPER FEATURES Manufactured by Bravo Company MFG, Inc. (BCM) Fully assembled, headspaced, and test-fired Features BCM’s proprietary MK2 upper receiver for enhanced rigidity Relocated forward assist for easier charging handle access M4 feed ramp barrel extension and upper receiver for reliable feeding T-marked upper receiver for easy configuration of tactical accessories Mil-Spec barrel steel (Certified Mil-B-11595E) for strength and durability Chrome bore and chamber for enhanced chambering, extraction, and reliability Manganese phosphate barrel finish for corrosion resistance HPT / MP Inspected barrels for quality assurance and flaw detection BOLT CARRIER FEATURES BCM (MPI) complete bolt carrier group for AR-15, M16, or M4 Parkerized exterior with chrome-lined inside carrier Machined to USGI specifications, Full Auto Profile M16/M4 carrier with Mil-Spec chrome-lined gas key Gas key heat-treated and chrome-lined, securely fastened with grade 8 fasteners Bolt assembly machined from Mil-Spec Carpenter No. 158 steel, shot peened Includes tool steel extractor and ejector Includes BCM extractor spring HPT (High-Pressure Tested) and MPI (Magnetic Particle Inspected) BCM test fires for function before shipping Upper Specifications Caliber 300 Blackout Barrel Material 11595E Spec Steel Barrel Finish Manganese Phosphate (Mil-Spec A-A-59267) Bore & Chamber Chrome Lined Twist Rate: 1:7 Gas System Pistol Muzzle Device BCM® Comp Mod 1 (762/300BLK) Muzzle Threads 5/8×24 Made in the USA. BUFFER RECOMMENDATIONS INDEX: Sprinco Hot White: In the middle of a standard carbine spring and the Blue spring, roughly 7-8% stiffer than standard. Sprinco Blue: 15% stiffer than standard carbine springs. Sprinco Green: Rifle length spring for A5/MK2 buffer systems. MK2 9″, MCMR-8, Standard Barrel – Continuous Taper Profile, Pistol Gas Unsuppressed Supersonic Carbine: H1 or H2 – Standard or Sprinco Hot White Spring Vltor A5/BCM MK2: -A5H2/T2 – Rifle or Sprinco Green Spring Law Folder, Carbine: H1 or H2 – Standard Spring Law Folder, Vltor A5/BCM MK2: A5H1/T1 or A5H2/T2 – Rifle or Sprinco Green Spring Suppressed Supersonic Carbine: H2 or H3 – Standard or Sprinco Hot White Spring Vltor A5/BCM MK2: – A5H3/T3 – Rifle or Sprinco Green Spring Law Folder, Carbine: H1 or H2 – Standard Spring Law Folder, Vltor A5/BCM MK2: A5H2/T2 or A5H3/T3 – Rifle or Sprinco Green Spring Suppressed Subsonic Carbine: Carbine (3.0oz) or H1 – Standard Spring Vltor A5/BCM MK2: A5H1/T1 – Rifle or Sprinco Green Spring Law Folder, Carbine: Carbine (3.0oz) – Standard Spring Law Folder, Vltor A5/BCM MK2: A5H0/T0 or A5H1/T1 – Rifle or Sprinco Green Spring 50/50 Subsonic / Supersonic Suppressed Carbine: H1 – Standard or Sprinco Hot White Spring Vltor A5/BCM MK2: A5H1/T1 – Rifle or Sprinco Green Spring Law Folder, Carbine: Carbine (3.0oz) or H1 – Standard Spring Law Folder, Vltor A5/BCM MK2: A5H0/T0 or A5H1/T1 – Rifle or Sprinco Green Spring ** These are approximations. Due to the wide operating range of 300 Blackout it is recommended to do your own testing and confirm functionality. It’s also recommended to shoot the rifle for roughly 200-300 rounds to allow proper break-in and gas system sealing before arriving at a final buffer setup. TECHNICAL SPECIFICATIONS Specifications MK2 9″, MCMR-8, Standard Barrel, Pistol Gas MK2 9″, MCMR-8, Standard Barrel, Pistol Gas Weight 3 lb 1.9 oz with Radian Raptor 3 lb 4.5 oz with Radian Raptor Weight, Standard Lower – No Stock 4 lb 13.4 oz with Radian Raptor 5lb with Radian Raptor Weight, Standard Lower – Law Folder, No Stock 5 lb 8.5 oz with Radian Raptor 5 lb 11.1 oz with Radian Raptor Length, Upper Only 17.75″ Muzzle Device to End Of Receiver 17.75″ Muzzle Device to End Of Receiver Length, Standard Lower – No Stock 25.18″ Muzzle Device to End Of Carbine Extension 25.18″ Muzzle Device to End Of Carbine Extension Length, Standard Lower – Law Folder, No Stock 26.38″ Muzzle Device to End Of Carbine Extension 26.38″ Muzzle Device to End Of Carbine Extension Length, Standard Lower – Law Folder, No Stock (Folded) 19.69″ Muzzle Device to Furthest point 19.69″ Muzzle Device to Furthest point