Though it carries a name festooned in ancient calibre history, it will come as a surprise to many that the .450 Rigby is actually a relatively new cartridge, launched by Rigby in 1995. This came almost 100 years after it introduced the .450 Nitro Express.
It was an elephant hunting trip by Mr Paul Roberts, the owner of Rigby, that led to the development of this cartridge. He landed a well-placed lung shot with a .416 Rigby, and the elephant cow moved on a considerable distance before succumbing to several more shots. Disappointed with the performance of his round, Paul immediately started a fevered post-hunt discussion with his PH. He concluded that extra weight and bullet diameter would be beneficial for taming the earth’s largest land mammal.
The solution was tidy. Necking up the .416 case to .458, the already generous capacity would be able push a 480-grain bullet with moderate pressure at 2,400fps. Given that Rigby already manufactured many rifles for the highly regarded .416, simply necking up this cartridge required minimal additional manufacturing expense or design development.
There are, however, a few downsides to using the already established brass. For one thing, it is terribly inefficient with modern powders. It also requires the use of magnum-length actions and non-standard magazine widths to accommodate the fat cases. Powder consumption is also a consideration. According to QuickLoad, the .450 Rigby requires 96.8 grains of N550 to push out a 500-grain Woodleigh at 2,271fps. With a .458 Lott, similar velocities can be achieved with the same bullet and 76-grain N530. However, the Rigby does allow for far greater performance if the recoil can be handled, punching out 500 grains of copper and lead at 2,427fps with a 103.5-grain load of N550. It does this with considerably less chamber pressure than the Lott – 57,838psi compared with 62,141psi – yet sends the same bullet down range at 156fps more.
On paper, the recoil of the Rigby does seem punishing. For the comparable loads above, the .450 pushes back with 79.6ft/lb. Cranking a 2,427fps load out of the Rigby escalates this considerably, packing an unpleasant 91.4ft/lb of recoil. For those who are unacquainted with calibres of this size, the recoil of a .243 Win will be around 8.8ft/lb.
Despite this colossal difference, the .450 Rigby is surprisingly manageable. I remember being stunned on squeezing off the first round at just how easy it was to handle this large calibre. I wouldn’t describe the recoil as severe – more like exhilarating. Unlike some big calibres that kick you abruptly with head-snatching violence, this was more of a long, hard push. Needless to say, I had already become a fan at this point.
With reliable and smooth cycling due to the rimless case, moderate pressures and availability of excellent .458 bullets, the Rigby has already forged itself an enviable reputation in what is a very short space of time. Welcome to the .450 Rigby – a modern great. BP