.450 Bushmaster Load Data

The .450 Bushmaster is a relatively modern cartridge with roots that trace back to the early 2000s. Its inception arose from a collaboration between Tim LeGendre of LeMag Firearms and Hornady Manufacturing, aiming to satisfy the “Thumper” concept initially popularized by firearms expert Jeff Cooper. Cooper envisioned a heavy-hitting, straight-walled cartridge for semi-automatic rifles, suitable for hunting larger game in areas with restricted rifle regulations. Remington first introduced the cartridge officially, but it was Bushmaster Firearms that adopted and championed it, tailoring it specifically for the AR-15 platform. With a rimless, straight-wall design and a large .45 caliber bullet diameter, the .450 Bushmaster rapidly gained traction with hunters and shooters seeking big-bore performance, especially in jurisdictions that restrict the use of bottleneck cartridges during certain hunting seasons.

Applications for the .450 Bushmaster center around both hunting and tactical use. In the hunting arena, the cartridge delivers substantial stopping power at medium ranges, making it highly effective for large game. Its compatibility with the popular AR-15 platform allows shooters to utilize familiar ergonomics with increased ballistic performance, essentially transforming a standard .223/5.56 AR-15 into a short-range, heavy-hitting hunting rifle. The .450 Bushmaster’s manageable recoil compared to bigger-bore bolt actions has also made it attractive for shooters who want power without excessive shoulder punishment. The cartridge is likewise appreciated for its utility in states like Ohio, Indiana, and Michigan, where hunting regulations require straight-walled cartridges for deer hunting. This specificity opened up new markets for the caliber and significantly boosted its popularity among reloading enthusiasts and hunters alike.

When it comes to target species, the .450 Bushmaster excels at harvesting medium to large North American game. Deer hunting is its most common application, especially in straight-wall cartridge states, but the power and terminal ballistics of its .45-caliber projectiles make it equally suitable for black bear and feral hogs. Some hunters have even used it successfully on elk at moderate ranges, though it’s ideal for engagements within 200 yards due to its relatively modest velocity and energy retention at extended distances. The stopping power delivered by the 250- to 300-grain bullets ensures deep penetration and quick, humane kills on even the toughest quarry, provided the shooter stays within ethical range limitations.

Reloaders working with the .450 Bushmaster typically focus on bullet weights ranging from 200 grains up to 300 grains, with 250 grains being the most common. Factory ammunition from major brands like Hornady features pointed Flex Tip bullets in this weight class, optimizing both feeding and downrange performance. The cartridge operates at a maximum pressure of 38,500 psi, offering a good blend of velocity and power from barrels as short as 16 inches. Its straight-wall case makes it straightforward to reload, and its rebated rim facilitates reliable feeding from modified AR-style magazines. Typical muzzle velocities for standard loads hover around 2,200 fps with a 250-grain bullet, delivering over 2,600 ft-lbs of energy, which is considerable for deer and similar game. Reloaders benefit from a variety of available powders and projectiles, allowing them to tailor loads for both hunting and range work, maximizing the versatility of this hard-hitting, modern bush cartridge.