.700 Nitro Express

Wednesday, April 29th, 2020

.700 Nitro Express

In 1988 Jim Bell and Willian Feldstein approached Holland and Holland with the .700 Nitro Express. It is an original design and not based on altering any exiting cartridge. The design originated after Feldstein asked Holland & Holland to make a .600 Nitro Express for him. They refused because the company had officially made its last one. Holland and Holland was seeking a new big bore cartridge and the .700 Nitro Express fit the bill.

This new cartridge is based on scaling up the .600 Nitro Express and is a full ½” longer, according to Bell. It is the most powerful production sporting cartridge in the world and has a Taylor Knockout Value of 200. It is capable of propelling a .700 in. dia. 1,000 grain bullet at 2,000 fps with 8,900 ft.-lbs. of energy. It is more than adequate for any known large game animal.

The Taylor Knockout Value is a mathematical formula developed by John “Pondoro” Taylor to evaluate the knockout power of a cartridge. Here’s the formula:

Example calculation

Using the standard 7.62×51mm NATO cartridge, the cartridge’s characteristics are:

Bullet mass = 9.5 grams {\displaystyle \Rightarrow } 147 grains

Muzzle velocity = 833 meters per second {\displaystyle \Rightarrow } 2733 feet per second

Bullet diameter = 7.82 millimeters {\displaystyle \Rightarrow } .308 inches

The calculation is:

Therefore the Taylor KO factor for the 7.62x51mm NATO cartridge is 17.9.

Roberson Cartridge Company is a custom manufacture of Vintage, Obsolete, Hard to Find and Wildcat calibers.

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