Brownells .458 SOCOM and .450 Bushmaster AR-15 Barrels

    Brownells 450 Bushmaster AR-15 Barrels (4)

    Brownells has introduced big bore AR-15 barrels chambered in .458 SOCOM and .450 Bushmaster. The barrels for both caliber options come with the bolts and three-chamber muzzle brakes. Apparently these are custom profile barrels made by Faxon Firearms specifically for Brownells. In a recently published new products announcement video, Brownells’ employee Paul Levy says: “these are specific profiles that we requested from Faxon“. You can find that video embedded below.

    Overall, the two barrels have virtually identical features with minor differences. Let’s take a closer look at each of them.

    Brownells .458 SOCOM AR-15 Barrel

    Brownells .458 SOCOM AR-15 Barrels (2)

    The .458 SOCOM barrel is made of 4150 mil-spec steel. These are 16″ button rifled barrels. After being machined from a rifled barrel blank, the barrels then get stress relieved and nitrided. These barrels are also magnetic particle inspected.

    Brownells 450 Bushmaster AR-15 Barrels (5)

    Brownells .458 SOCOM barrels have 1:14 twist rate and 11-degree muzzle crown. Although Brownells doesn’t specify the thread pitch of the muzzle threads, I think it is most likely 11/16×24 TPI because big bore Faxon Firearms barrels are threaded with that thread pitch. The gas block portion of these barrels has .750 diameter.

    Brownells .458 SOCOM AR-15 Barrels (3)

    Muzzle brakes that come with new Brownells big bore AR-15 barrels look to have the Faxon MUZZLOK attachment systems. The latter consists of a separate lock nut at the base of the muzzle device which allows to time and install the muzzle device without using a crush washer or shims.

    The whole package including the barrel, bolt and muzzle brake is listed on Brownells website at $309.99.

    Brownells .450 Bushmaster AR-15 Barrel

    Brownells 450 Bushmaster AR-15 Barrels (2)

    As mentioned above, the .458 SOCOM and .450 Bushmaster barrels share most of the features. They are made of the same material and have the same finish/surface treatment. The .450 Bushmaster barrels also have 16″ length and perhaps the only difference is that the .450 Bushmaster barrels have 1:16 twist rate.

    The price for the .450 Bushmaster barrel is also $309.99.

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    Hrachya H

    Being a lifelong firearms enthusiast, Hrachya always enjoys studying design, technology and history of guns and ammunition. His knowledge of Russian allows him to translate and make Russian/Soviet/Combloc small arms related information available for the English speaking audience. Hrachya also writes for
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