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Rifle Parts Barrel Parts Rifle Barrels CMMG AR15 12.5" 300BLK MR BARREL Support

Upgrade your AR-15 to 300 AAC Blackout with CMMG's 12.5" barrel, featuring 1-7" rifling and Wasp nitride finish for durability and performance.

CMMG AR15 12.5" 300BLK MR BARREL

815835062761 100014823

Filters:

Variations
Filters:
Variations:

Variations:

Upgrade your AR-15 to 300 AAC Blackout with CMMG's 12.5" barrel, featuring 1-7" rifling and Wasp nitride finish for durability and performance.
AR-15/M16 300 BLK BARRELS - AR15 12.5" 300BLK MR BARREL
269.9 GBP 0 £269.90 *
Backorderable
Cartridge: 300 AAC Blackout Contour: Medium Finish: Nitride Gas System Length: Pistol Length: 12.5'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100014823
Backorderable
269.9 GBP 0 £269.90 *
Upgrade your AR-15 to .300 AAC Blackout with this 16" CMMG barrel, offering 7.62 x 39 ballistics and compatibility with standard AR components.
AR-15/M16 300 BLK BARRELS - BARREL STRIPPED 16" M300 LE AAC W/CAR GAS
199.9 GBP 0 £199.90 *
Not available
Barrel Weight: 2.205 lbs Cartridge: 300 AAC Blackout Contour: Medium Finish: Black Gas System Length: Carbine Length: 16'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100009125
Not available
199.9 GBP 0 £199.90 *
Upgrade your AR-15 to 300 AAC Blackout with CMMG's 8.2" barrel, featuring 1-7" rifling, Wasp nitride finish, and compatibility with standard AR components.
AR-15/M16 300 BLK BARRELS - AR15 8.2" 300BLK MR BARREL
234.9 GBP 0 £234.90 *
Not available
Cartridge: 300 AAC Blackout Contour: Medium Finish: Nitride Gas System Length: Pistol Length: 8.2'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100014824
Not available
234.9 GBP 0 £234.90 *
199.9 269.9 3 GBP
269.9 GBP £269.90

Prices inclusive of duty & VAT.

Product no.: 100014823

Mfr. No.: 30D8A0A

815835062761 Direct replacement for the standard .223/5.56mm barrel converts your AR-15 to the high-performance 300 AAC Blackout (300BLK) cartridge. The 300 AAC lets you upgrade your rifle to 7.62 x 39 ballistics, while retaining the standard AR-15/M16 bolt, carrier, and magazine at its full capacity, with no additional modifications. 1-7" rifling accepts bullet weights from 110 gr to 220 gr, and 5/8"-24 muzzle threads accept popular AR-.308 flash suppressors and muzzle brakes. Three models available, 16", 12.5" and 8.2" long and treated inside and out with CMMG’s "Wasp" nitriding process for outstanding resistance to wear and corrosion. 16" barrel has the gas port in the standard position for use with all M4-length gas systems and supersonic ammunition. 12.5" & 8.2" barrels have the gas port positioned for use with pistol-length gas systems.
Backorderable
3.6/5 - 5 Customers

Backorderable, delivery time approx. 4-12 weeks from the USA warehouse.

100-Day Return Policy
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199.9 269.9 3 GBP
Description Specification Customers reviews Accessories

CMMG AR15 12.5" 300BLK MR BARREL

269.9 GBP £269.90

Prices inclusive of duty & VAT.

Is a 'Call to order' product.
Requires order by phone

Description:

Transform Your AR-15 Into A .30 Caliber Powerhouse

Upgrade your firearm with the CMMG AR15 12.5" 300BLK MR BARREL, designed for those who demand high performance without the need for extensive modifications.

Product Description

This barrel serves as a direct replacement for the standard .223/5.56mm barrel, allowing you to convert your AR-15 to the impressive 300 AAC Blackout (300BLK) cartridge. The 300 AAC Blackout enhances your rifle's capabilities to match 7.62 x 39 ballistics while maintaining compatibility with the standard AR-15/M16 bolt, carrier, and magazine at full capacity, all without additional modifications.

  • Rifling: 1-7" rifling that accommodates bullet weights from 110 gr to 220 gr.
  • Muzzle Threads: 5/8"-24 threads compatible with popular AR-.308 flash suppressors and muzzle brakes.
  • Available Lengths: Choose from 16", 12.5", and 8.2" models.
  • Durability: Treated inside and out with CMMG’s "Wasp" nitriding process for exceptional wear and corrosion resistance.
  • Gas Port Position: 16" barrel has the gas port in the standard position for M4-length gas systems and supersonic ammunition; 12.5" & 8.2" barrels are designed for use with pistol-length gas systems.

Specifications

  • Material: Hardened 4140 chrome-moly steel
  • Finish: Wasp nitride finish in matte black
  • Outer Diameter: .750" O.D. at gas port
  • Muzzle Threads: 5/8-24

Elevate your shooting experience with the CMMG AR15 300 BLK BARREL—where performance meets reliability.



Restrictions

  • Is a 'Call to order' product.

Top takeaways

  1. Converts AR-15 to 300 AAC Blackout using standard bolt, carrier, and magazine without additional modifications.
  2. Features a 12.5" medium contour barrel with 1-7" twist, suitable for 110 gr to 220 gr bullets, and a pistol-length gas system.
  3. Constructed from hardened 4140 chrome-moly steel with a nitride finish for superior wear and corrosion resistance.

Attributes

  • Barrel Weight: -
  • Cartridge: 
    300 AAC Blackout
  • Contour: 
    Medium
  • Finish: 
    Nitride
  • Gas System Length: 
    Pistol
  • Length: 
    12.5''
  • Muzzle Threads: 
    5/8-24
  • Twist: 
    1-7
  • Weapon type: 
    AR-15
  • Delivery weight: 0.816kg
  • Shipping height: 26mm
  • Shipping width: 28mm
  • Shipping length: 436mm
  • UPC: 815835062761

Item details

Made in USA
US export classification: 0A501.c

Customers reviews

Customer ratings (5)

3.6 / 5
Recommended

Brownells USA Awesome barrel 11/07/2014

I was looking for a lighter weight barrel for a carbine project, CMMG makes this one at a weight of only 1.8# and coupled with a Midwest Industries 10" lightweight kemod rail the rifle turned out to be all I expected. Sight in with iron sights took five shots and from that point my old eyes could easily keep it in the black. This rifle will be tested on Texas hogs soon.

Not recommended

Brownells USA 2 barrels will not head space 17/02/2014

I was building a pair of rifles for friends. I have built 300 AAC rifles using the Brownells barrel with no issues. The fit and finish on these barrels looked great but they would not head space with the "go" gauge. I tried several bolts from several manufacturers including a well used Colt bolt. These chambers are way off!

Variations:

Upgrade your AR-15 to 300 AAC Blackout with CMMG's 12.5" barrel, featuring 1-7" rifling and Wasp nitride finish for durability and performance.
AR-15/M16 300 BLK BARRELS - AR15 12.5" 300BLK MR BARREL
269.9 GBP 0 £269.90 *
Backorderable
Cartridge: 300 AAC Blackout Contour: Medium Finish: Nitride Gas System Length: Pistol Length: 12.5'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100014823
Backorderable
269.9 GBP 0 £269.90 *
Upgrade your AR-15 to .300 AAC Blackout with this 16" CMMG barrel, offering 7.62 x 39 ballistics and compatibility with standard AR components.
AR-15/M16 300 BLK BARRELS - BARREL STRIPPED 16" M300 LE AAC W/CAR GAS
199.9 GBP 0 £199.90 *
Not available
Barrel Weight: 2.205 lbs Cartridge: 300 AAC Blackout Contour: Medium Finish: Black Gas System Length: Carbine Length: 16'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100009125
Not available
199.9 GBP 0 £199.90 *
Upgrade your AR-15 to 300 AAC Blackout with CMMG's 8.2" barrel, featuring 1-7" rifling, Wasp nitride finish, and compatibility with standard AR components.
AR-15/M16 300 BLK BARRELS - AR15 8.2" 300BLK MR BARREL
234.9 GBP 0 £234.90 *
Not available
Cartridge: 300 AAC Blackout Contour: Medium Finish: Nitride Gas System Length: Pistol Length: 8.2'' Make: AR-15 Muzzle Threads: 5/8-24 Twist: 1-7 Product no.: 100014824
Not available
234.9 GBP 0 £234.90 *

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