August 13, 2020
By Steve Gash
A unique load for the .450 Bushmaster is Hornady ’s new Subsonic offering. It’s loaded with the company’s 395-grain Sub-X (Subsonic–eXpanding) bullet that is designed to expand and penetrate but not break up. Hornady says it’s “silent and stealthy.”
The Sub-X load uses a low-flash propellant that won’t hinder low-light vision and that is also quiet (with a suppressor installed on the rifle, it’s even quieter). The Sub-X bullet has a Flex Tip insert to help initiate expansion and longitudinal grooves in the gilding metal jacket.
This fat bullet has an impressive ballistic coefficient of .300 and a sectional density of .276 that aids penetration. The listed factory velocity is 1,050 fps from a 24-inch barrel. Out of the Rock River Arms LAR-15M I used for this report, which has a 16-inch barrel, the round’s average velocity was 1,005 fps. That’s for five rounds measured 10 feet from the gun’s muzzle with an Oehler Model 35P chronograph.
As for accuracy, the load averaged 1.47 inches for three, five-shot groups at 100 yards. That’s about middle of the pack for this carbine. Hornady’s Subsonic .450 Bushmaster load hits 9.5 inches lower than the company’s 250- and 260-grain loads, and it would not cycle the LAR-15M’s action. Hornady notes that functioning with subsonic ammo is totally dependent on the gun’s gas system.
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NOTES: Accuracy is the average of three, five-shot groups fired from a benchrest. Velocity is the average of five rounds measured 10 feet from the gun’s muzzle. Range temperature was 45 to 64 degrees Fahrenheit. Hornady’s Subsonic line also includes .300 Blackout, .30-30 Win., and .45-70 Gov’t rifle cartridges and 9mm Luger, .40 S&W, and .45 ACP handgun chamberings.
MSRP: $39.72; hornady.com
