.700 Nitro Express
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|.700 Nitro Express|
.700 Nitro Express cartridge
|Type||Big Game Rifle|
|Place of origin||United Kingdom|
|Designer||Jim Bell / William Feldstein|
|Case type||Rimmed, straight|
|Bullet diameter||.700 in (17.8 mm)|
|Neck diameter||.730 in (18.5 mm)|
|Base diameter||.780 in (19.8 mm)|
|Rim diameter||.890 in (22.6 mm)|
|Rim thickness||.060 in (1.5 mm)|
|Case length||3.50 in (89 mm)|
|Overall length||4.20 in (107 mm)|
|Case capacity||316.9 gr H2O (20.53 cm3)|
|Primer type||Boxer; Magnum Large Rifle|
|Source(s): Kynoch |
The .700 Nitro Express (17.8×89mmR) is a big game rifle cartridge made by Holland & Holland, London, England. It was developed in 1988 by Jim Bell and William Feldstein and built by H&H. Feldstein had tried unsuccessfully to get H&H to build a .600 Nitro Express for him, but they had already ceased production. However, when Bell and Feldstein produced the entirely new .700 Nitro Express cartridge, they were able to attract the interest of H&H, who was looking for a new big-bore cartridge. After production began, the backlog of orders was so great that it continues to this time (2007) and H&H has even restarted the production of .600 Nitro Express guns. 
In many respects this cartridge parallels the .600 Nitro Express. It is essentially a scaled-up version of that cartridge, but is somewhat more powerful, and fires a heavier 1000-grain (64.8 g) bullet. The case itself is a completely new case, not simply another case resized. Double rifles are extremely expensive, selling upwards of $60,000 USD in 2005, and have generally been replaced by repeater-rifles using rounds such as the .458 Winchester.
Single factory loaded .700 Nitro cartridges are available, typically at $100 USD each, although they have been sold on the internet for as little as $50 USD. .700 Nitro cases, like those of other big bore cartridges, can be hand reloaded, drastically reducing the cost.
The .700 Nitro Express develops an approximate average of 8,900 foot-pounds force (12,100 J) of muzzle energy with a 1,000 gr (65 g) bullet at 2,000 ft/s (610 m/s). However handloaders can push the cartridge to generate as much as 15,000 foot-pounds (20,000 J) of energy in a modern bolt action, by using a 1,000 gr (65 g) bullet fired at 2,600 ft/s (792 m/s). However, doing so necessitates a rifle so heavy it is almost inoperable for hunting purposes. Lathe turned cases as used in the Accurate Reloading rifle above will suffer blown primers at this level though a good source of drawn brass would allow (in theory) velocities up to 2,700 ft/s (820 m/s).
The typical average muzzle velocity of a factory-loaded cartridge is 2,000 ft/s (610 m/s). In the 18 pounds (8.2 kg) rifle used by Accurate Reloading this would result in recoil energy of approximately 160 ft·lbf (220 J). This is more than ten times the average recoil from a .308 Winchester which is a very common hunting calibre, and more than 4 times the recoil of a strong .45-70 Government round.
Rifle calibers comparable to the .700 Nitro Express in terms of power and recoil include the following:
- .600 Nitro Express
- .600 Overkill
- .585 Gehringer
- .585 Nyati
- .577 Tyrannosaur
- .475 A&M Magnum
- .460 Weatherby Magnum
- .50 BMG
- .950 JDJ (the world's largest rifle cartridge)
- 20x102mm Vulcan (One of the most powerful rifle rounds, used in anti-materiel rifles)
- Cooper, Jeff. ".700 Nitro Express". Guns&Ammo. Retrieved 7 September 2010.
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