You have to remember there was a time when the early failures of the 458 Winchester were still fresh in everyone's mind, and rifle builders, ammo makers, gun writers and PH's were all looking for a solution. Ammunition for many of the older Nitro Express and British bolt action cartridges was drying up, and many were casting about for suitable replacements.
In 1970, the 416 Rigby and 505 Gibbs were on their last legs, rifles and ammo for the 470 and 500 NE were almost non existent in North America and the future didn't look bright for them ever returning.
Weatherby magnums were well known, but the expensive, flashy rifles and excessive recoil turned most shooters off to them immediately. Add to that the bullets of the time performed poorly at the velocity the Weatherbys were loaded to and sales were modest at best.
Then enter Paul Roberts who had purchased Rigby, Kenny Jarrett, Dakota rifles and others, who took the 416 Rigby case, and necked it to hold .458 bullets. All of them had the same idea all at the same time. A moderately large case smaller than the NE cartridges, but larger than a standard belted magnum, that could be chambered in a true Magnum Mauser sized action, and push a 500 grain .458 dia bullet to 2400fps with moderate pressure.
If you set the 460 Wby, 450 Dakota and 450 Rigby side by side, they are almost identical with the exception of the magnum belt on the Weatherby. Case taper, shoulder angle and pressure level are what separate them, but the designer had the same goal in mind with each of them. When so many people perceived the same need, and came up with almost the same answer, that should tell you something.
The 450 Rigby may fade as factory produced ammo for a while, but will maintain a loyal following among PH'S and hunters that want more stomp than the 416's, or the 458 Win.
Park West, Jerrett, Rigby and dozens of others produce rifles in 450 Rigby even now. Do you think they build rifles with the thought that they could never be supplied with ammunition?
