Just noticed this new factory load for the 450b on ammoseek.com from XCaliber Ammunition: its a 225gr FTX at 2300fps...
http://www.buygunsandammo.com/rifle-amm ... ounds.html
http://xcaliberammo.com/
XCaliber is happy to announce the 450 Bushmaster with Hornady's Flex Tip Expanding (FTX) bullets. These bullets feature an interlocking design that keeps the core of the bullet and the jacket together, creating a deeper penetrating and more humane kill. Great for hunting any North American quarry, this cartridge will provide controlled expansion, enhanced accuracy and flatter trajectories, shot after shot. This ammunition is new production, non-corrosive, in boxer primed, reloadable brass cases.
Additional Information
Manufacturer XCaliber
Caliber .450 Bushmaster
Number Rounds 20
Case Type brass
Bullet Type FTX
Bullet Weight 225 Grain
Muzzle Velocity 2297 FPS
$25.99/20