2.5-inch .450 Bushmaster muzzle brake in standard 11/16x24 thread, listed for the Ruger American 450.

Affiliate links (?)
Compare current prices and availability from retailers we work with.
Next Level Armament designed the NLX-11 after building its own .450 Bushmaster rifle and finding the recoil and muzzle rise needed taming. The production brake is 2.5 inches long and 0.88 inches in diameter, nitride finished, and threaded 11/16x24, the standard .450 Bushmaster muzzle thread. Next Level lists it as compatible with the Ruger American .450 Bushmaster bolt rifle as well as AR-15 builds.
Installation needs care. The crush washer for a thread this large is thin, so Next Level says to hand tighten and then index with no more than one third of a turn, or the washer can snap. Index it with the solid ridge up and the ports at 11 and 1 o'clock rather than by the logo, since thread timing varies between barrels.

Next Level Armament
Next Level Armament NLX-5 Hi-Helix Flash Suppressor (5.56, 1/2x28)
$60

Next Level Armament
Next Level Armament NLX-7 Alice Spiked Comp/Flash Suppressor (5.56, 1/2x28)
$75
Next Level Armament
Next Level Armament NLX-7NS Heretic Comp/Flash Suppressor (5.56, 1/2x28)
$75

Next Level Armament
Next Level Armament NLX-9 Speed Brake (5.56, 1/2x28)
$75
Add the Next Level Armament NLX-11 450 Bushmaster Brake (11/16x24) to your build and see how it enhances your platform.