The 450 G&A is a shortened version of the 460 G&A. It is designed to feed out of a mag box with the length of the 458 Win. Uses a 404 Jeff cartridge slightly blown out. About 2.5” case length. Shoulder is about 17.5 degrees.
Today you can get something pretty close by necking up a 416 Ruger.
The 460 version is close to 375 H&H length both case and overall.
The 450 easily get 2150 with a 500 grain. But a 458 Win will easily do that with currently available powders.
I would get a 458 Win. It is plenty.
Why wouldn't the .450 G & A easily outperform the .458 Win with same powders and same throating, seating depth and same barrel length? The case holds more.
