You may have noticed that most of the double rifle cartridges are launching the projectiles at or near 2150 fps. The amount of pressure to do this is dependant on the case volume. A 458 WM produces 18 tones and a 450 No2 11 tones to attain the same velocity. A quick study of the Ideal Gas Law (PV=nRT) will shed some light.

In regards to a break open action, the back thrust of the case causes the frame to asymmetrically flex and stretch. It’s this tweaking that contributes to a rifle coming of face.

When one starts talking about high velocity small bore cartridges, high pressure becomes the bug-a-bear.

A .350 cartridge with the ballistics of a .35 Whelan and pressure of a 450-400 is darn near ideal in my book. It’s called the .350 Rigby