The CheyTac Intervention is an American bolt action sniper rifle manufactured by Randy Kobzeff for long range soft target interdiction. It is fed by a detachable single stack magazine, which holds 7 rounds. It fires .408 CheyTac or .375 CheyTac ammunition. CheyTac papers state that the entire system is capable of delivering sub-MOA accuracy at ranges of up to 2,500 yards (2,300 m), one of the longest ranges of all modern-day sniper rifles. It is based on the EDM Arms Windrunner.
Long Range Rifle System
The M200 Intervention rifle is part of CheyTac's "Long Range Rifle System" which includes specially developed rifle cartridges loaded with also specially developed very-low-drag bullets, the CheyTac tactical ballistic computer, (commercial PDA with CheyTac ballistic software), the Kestrel 4000 or 4500 Pocket Weather Tracker that finds wind, temperature, humidity, and atmospheric pressure, and can be linked to the PDA, the Vector IV laser rangefinder that can be linked to the PDA, the Nightforce NXS 5.5-22x56, telescopic sight and a muzzle brake and suppressor to form Chey-Tac's Long-Range Rifle System.
Cartridge, bullets and barrels
CheyTac L.L.C. researched the optimum cartridge case, bullet and barrel configuration for very long range use. For this the .408 Chey Tac cartridge was developed that fires very-low-drag mono metal bullets that were specially designed for the Long Range Rifle System by the now (2010) defunct company Lost River Ballistic Technologies.
Lost River Ballistic Technologies (statement of the inventor Mr. Warren Jensen) stated that "the .408 Chey Tac was the first bullet/rifle system that utilizes a balanced flight projectile. To achieve balanced flight the linear drag has to be balanced with the rotational drag to keep the very fine nose (meplat) of the bullet pointed directly into the oncoming air. It should result in very little precession and yaw at extreme range and allows accurate flight back through the transonic region. This is hard to achieve for small arms projectiles. Mathematically you are at a great disadvantage trying to achieve balanced flight with a lead core non mono metal bullet. The rotational mass/surface area ratio is too high".
The balanced flight projectile patent can be found at the US Patent Office, Controlled spin projectile, US PAT No. 6,629,669. According to the patent a projectile engraved and launched according to the teachings of the patented invention should decelerate from supersonic flight through transonic to subsonic in a stable and predictable manner effective to a range beyond 3,000 yards (2,743 m). It implies that amongst several other preconditions the rifle barrel has to have specific rifling dimensions to achieve a desired amount of axial air drag on the bullets surface, which reduces the bullets spinrate to achieve balanced flight.
To achieve balanced flight the rifling twist rate for the .408 Chey Tac chambering was chosen at 330.2 mm (1 in 13 in) with 8 0.4080 in diameter grooves, 0.4010 in diameter bore and a 0.050" land width, square cut, with no taper. The later from the .408 Chey Tac developed .375 Chey Tac chambering uses a 292 mm (1:11.5 in) rifling twist rate.
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World's Top 10 Sniper Riflesby WhoDaresWins164675,856 views
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