After roughly ten years of development, Roy Weatherby launched the 224 Weatherby Magnum in 1963 as a sports cartridge. The 224 Weatherby Magnum was a scaled-down variant of the 300 Weatherby Magnum, with nearly comparable ballistics to the 22-250. To get the most power out of the 224, the chambers were lengthened to allow for a longer peak pressure to build up bullet speed (a necessity of the RUM cartridges also).
The 224 was phased out of the market when Remington launched the 22-250 in 1965. The 224 Weatherby Magnum is a proprietary cartridge, with no other major firearms manufacturers chambering rifles for it. When it was first released alongside the Weatherby Varmintmaster rifle, it was called the 224 Weatherby Varmintmaster, but the rifle was decommissioned in 1994, and the cartridge was renamed.
The 224 Weatherby Magnum's performance was comparable to the popular 22-250 and the less common 225 Winchester, putting it somewhere between the 220 Swift and 223 Remington rounds. The 224, like other ultra-high-velocity 22 centerfire cartridges, is best suited to a game weighing up to 40kg (90lb), with a safe maximum of 60kg (130lb), while heavier game weighing up to 80kg (180lb) necessitates extremely precise shot placement. Because the 224 loses velocity quickly, wounding at 50 yards and injuring at 250 yards are considerably different. The ultra velocity 22's are great at long range as varmint cartridges, but their best performance as medium game cartridges is inside 125 yards.
3750fps with 50-grain bullets, 3700fps with the 53 grain Barnes TSX, and 3650fps with 55-grain bullets are all safe working velocities from the 26" barreled Weatherby. Many states in the US currently allow 22 caliber rifles to be used on big game, however, the bulk of them need a minimum of 6mm.