I have searched many prior posts trying to find out why 2400 fps is so important and can't find the answer. Who came up with this number and why is it the benchmark?

Probably because those ballistics will net you the magical 5000 ft/lbs of energy. It seems that cartridges which provide this energy level have proven, over the past hundred or so years, to be reliable and effective in the taking of large and dangerous african game.

Geronimo

quote:

Originally posted by eyeman:
I have searched many prior posts trying to find out why 2400 fps is so important and can't find the answer. Who came up with this number and why is it the benchmark?

Those are the ballistics the "original" .416 caliber - the .416 Rigby - delivered. For years this was considered the "holy grail" by a lot of African big game hunters. It seems this caliber delivered much of the versatility of the .375 H&H with the punch of the bigger bores. In addition, the Rigby delivers the 400grs@2400 fps ballistic at comparatively low pressure due to its large case, and the low pressure endeared the caliber to people who needed the ultimate reliability in the highest of temperatures.

For many years, .416 Rigby components, ammo and new rifles were scarce as hens' teeth. Very few calibers (if any) were available to bridge the gap between the (comparatively) small bore .375 H&H and the .458 Win Mag - which came with a bunch of problems of its own. Wildcats were created (such as the .416 Hoffman) which attempted to achieve Rigby ballistics, but due to the smaller cases available, they either struggled or pressures were considerably higher. In the late 1980s (or so?) Remington introduced their own "Rigby clone" - the .416 Rem - which also attempted to achieve Rigby ballistics - and pretty much succeeded, albeit at higher pressure. By then, the interest in .416 calibers was large enough for the Rigby to be "re-introduced" - with components, ammo and factory rifles all becoming available. So these days, it may seem odd why Rigby ballistics were considered a "big deal" for African big game hunting for such a long period of time. After all, these days you just walk out and buy a .416 Rigby...

- mike

2400fps is/was also considered the ideal velocity for hunting in bushveld with reliable bullet performance, little meat damage and good penetration. Multiply that up to 5000ft/lbs for DG and you have the magic formula for penetration, reliable bullet performance and knock-down power.