What Barrel Length Is Best for .450 Bushmaster?
Woody's answers are based on published federal and state law. Not legal advice. Consult a licensed attorney for your specific situation.
16-20 inches is the sweet spot for .450 Bushmaster. You get optimal velocity without excessive length, and the cartridge doesn't need a long barrel to burn its powder efficiently.
How This Affects Your Shooting
The .450 Bushmaster was designed as a straight-wall cartridge for AR-15 platforms, optimizing performance in shorter barrels compared to traditional rifle cartridges. Unlike high-velocity bottleneck cartridges that benefit from longer barrels, the .450 Bushmaster reaches peak efficiency relatively quickly due to its large bore diameter and moderate powder capacity.
The Detail
The .450 Bushmaster achieves most of its velocity potential within the first 16-18 inches of barrel length. This straight-wall cartridge burns its powder charge efficiently in shorter barrels because it uses relatively fast-burning powders and has a large bore diameter that allows for quick pressure release. You'll see diminishing returns beyond 20 inches, with minimal velocity gains that don't justify the added weight and handling challenges.
Barrels shorter than 16 inches will cost you noticeable velocity and energy, though the cartridge remains effective for close-range hunting. The large, heavy bullets maintain good terminal performance even at reduced velocities, but you're giving up range and hitting power. Most hunters find that going below 16 inches significantly limits their effective range for medium game.
The 18-20 inch range represents the performance peak for most .450 Bushmaster loads. You'll maximize the cartridge's potential energy while maintaining reasonable maneuverability. Beyond 20 inches, you're adding barrel length without meaningful ballistic improvement, and the weight distribution starts affecting the rifle's handling characteristics.
Barrel length also affects the rifle's intended role. If you're building a truck gun or close-quarters hunting rifle, 16 inches provides adequate performance with better maneuverability. For longer-range shots within the cartridge's effective envelope, 18-20 inches extracts maximum performance from your ammunition investment.
Build Impact
Choose 16 inches for a compact, maneuverable rifle or 18-20 inches for maximum ballistic performance. Going longer than 20 inches wastes money and adds unnecessary weight without meaningful velocity gains.