SilencerCo® Big Bore ASR™ Muzzle Brake – .338 Caliber – 5/8x24 – AC857
The SilencerCo® Big Bore ASR™ Muzzle Brake (AC857) is the 2026 industry-standard mounting foundation for heavy-hitting, large-caliber host rifles. Purpose-built to tame massive recoil impulses while serving as a rapid QD interface, this muzzle device is optimized specifically for big-bore platforms chambered in .338 Lapua Magnum, .338 Federal, 8.6 Blackout, and similar large-diameter cartridges. Machined from premium, high-tensile alloy steel and treated with a rugged matte black finish, the AC857 (817272011838) features standard 5/8x24 TPI muzzle threads, allowing it to adapt flawlessly to a wide variety of bolt-action precision rifles and heavy-barreled tactical carbines.
The core performance of the Big Bore ASR brake relies on a high-efficiency 3-port design. These expansive ports directionalize blast gases out to the sides, drastically reducing felt recoil and limiting muzzle climb to help precision shooters stay on target for second-shot correction. When it’s time to go quiet, the integrated Active Spring Retention (ASR™) collar system enables simple, secure, "one-hand-on, one-hand-off" installation of your suppressor. The mechanical taper lock guarantees zero point-of-impact shift and keeps the silencer tightly locked down against rotational loosening during intense strings of fire. It serves as an exact match for SilencerCo's premier large-caliber cans, including the Harvester 338, Omega 300, Omega 36M, and Hybrid 46 series.
Includes: (1) SilencerCo Big Bore ASR Muzzle Brake (.338 / 5/8x24), (1) Precision Timing Shim Set, and (1) Tube of Rocksett Threadlocker.
Key Features
- Big Bore Recoil Mitigation: Oversized 3-port architecture provides massive recoil reduction for violent .338 and 8.6mm class centerfire cartridges.
- Active Spring Retention (ASR™): Patented QD mounting interface allows for instant, reliable suppressor attachment and tool-less removal.
- Perfect Suppressor Concentricity: Precision machined to strict tolerances, ensuring exact bore alignment to completely eliminate the threat of baffle strikes.
- Concentric 5/8x24 Threads: Built for standard heavy-profile barrel threads common on modern long-range and tactical rifles.
- Includes Shim Kit & Rocksett: Ships with all the necessary timing hardware and high-temperature thread adhesive needed for a true professional installation.
- Versatile Suppressor Host: Native compatibility with SilencerCo Alpha, Bravo, and Charlie ASR mount adapters.
Product Specifications
- Brand: SilencerCo®
- Series: ASR™ Muzzle Brake (Big Bore / Harvester)
- SKU / MPN: AC857
- Caliber Compatibility: Up to .338 Caliber / 8.6mm Max
- Thread Pattern: 5/8"x24 TPI
- Interface Mount: SilencerCo ASR Quick-Detach
- Material: Heavy-Duty Hardened Alloy Steel
- Finish: Matte Black Melonite / Black Oxide
- Length: 2.45 Inches
- Weight: 3.50 oz (0.22 lbs)
- UPC: 817272011838
