- CheyTac Intervention
CheyTac Intervention M-200 rifle
Type Sniper rifle Place of origin United States Service history Used by See Users Production history Manufacturer CheyTac LLC Produced 2001—present Variants
- M-200 Carbine
- M-200 CIV (Civilian)
- M-200 RK
- M-310 SS (Single Shot)
- M-310 R (Repeater)
Specifications Weight 31 lb (14 kg) without scope (M-200) Length 53 in (1.34 m) (stock extended), 46¾ in (1.18 m) (stock collapsed) (M-200) Barrel length 29 (73.7 cm) in standard w/ 1:13 twist (M-200), 26 in (66 cm) optional. Cartridge .408 Chey Tac or .375 Chey Tac Action turn-bolt Effective range 2000+ m - M-200
2000+ m - M-200 Carbine
1500+ m - M-200 CIV (Civilian)
1800+ m - M-310 SS (Single Shot) )
1800+ m - M-310 R (Repeater)
Feed system 7-round detachable box magazine Sights day or night optics
The CheyTac Intervention is an American bolt action sniper rifle manufactured by CheyTac LLC 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.
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 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 specifications 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 bullet's surface, which reduces the bullet's spinrate to achieve balanced flight.
To achieve balanced flight the rifling twist rate for the .408 CheyTac chambering was chosen at 330.2 mm (1 in 13 in), with eight 0.4080 in diameter grooves, 0.4010 in diameter bore and a 0.050" land width, square cut, with no taper. The later .375 CheyTac round, developed from the .408 CheyTac, uses a 292 mm (1:11.5 in) rifling twist rate.
Muzzle brake and suppressor
The .408 CheyTac's light recoil is attributed to the McArthur PGRS-1 muzzle brake that was designed by gunsmith and firearm inventor, Bruce McArthur, owner of The Flint & Frizzen Gun Shop in Clarkston, Michigan. McArthur designed it to strip gases from the projectile before it leaves the muzzle brake.
The CheyTac muzzle brake suppressor, manufactured by OPS INC, is a stainless steel suppressor. The all stainless steel construction with no replaceable parts guarantees a suppressor life that equals or exceeds the life of the rifle. When totally filled with water, the suppressor can be drained in 6 seconds which allows use when emerging from water. If the operator chooses to switch to the muzzle brake, a repeatable 6 minute of arc zero change for elevation is required.
Day and night optical sight systems
There are two different day optical sights available. The primary sight is the Nightforce NXS 5.5-22x56 variable magnification telescopic sight with a 56 mm objective. The alternate sight is the US Optics SN-9. The night vision system chosen is the AN/PVS-14 GEN III Pinnacle monocular. The PVS-14 is attached to the day optic using the Monoloc device. An AN/PEQ-2 infrared laser is used for system support with the night vision sight under conditions where there is insufficient ambient light or the IR laser is needed for further target illumination. The device is attached to a titanium strut.
Meteorological and environmental sensor package
The KESTREL 4000 or 4500 (NV) meteorological and environmental sensor package is used to measure the wind, air temperature, and air pressure. It also collects relative humidity, wind chill, and dew point. All of these points of data are fed directly into the tactical computer so that no manual input is necessary. The KESTREL 4500 NV model has the capability to be used with night vision devices.
A Vector IV mil spec laser rangefinder is used to establish ranging data. This laser rangefinder can measure distance up to 6 km (3.7 mi), angles and also features a 360° digital compass and class 1 eye safe filters. The acquired data can be fed directly into the tactical computer. High end laser rangefinders that can very accurately measure distances over 2,000 m (2,200 yd) are prohibitively expensive for most civilian long-range shooters.
Advanced Ballistic Computer
The CheyTac Advanced Ballistic Computer (ABC) System software package was developed to enhance the long range predictive capabilities of a sniper’s handheld computer. According to the developers the softwares predictive capabilities are based on actual bullet flight data derived from test sessions on the high speed Weibel 1000e Doppler Radar at the U.S. Army Proving Grounds, Yuma Arizona. Engineers created algorithms that utilize both known mathematical ballistic models as well as test specific, tabular data in unison.
The system is said to provide the operator with a simple elevation and windage solution through complete integration of external environment, operator, and gun system specifications, enabling small arms weapons operators to produce highly accurate long-range trajectories to any number of specified targets at extreme ranges.
The software package is said to operate on a variety of consumer, hardened and mil-spec R-PDAs running the Windows Mobile 2003 operating system, using inputs from the Kestrel handheld weather station and Vector IV laser rangefinder binoculars.
However, much like other ballistic prediction software, when rounds are used for which no Doppler Radar-established bullet flight data is known, the ABC System relies solely on mathematical ballistic models like all other ballistic prediction computer programs.
Data tables in print are provided in the event the tactical ballistic computer fails or the batteries for the device fail. Without computer support the effectiveness of some long-range shooters could be severely reduced, since they may rely heavily on computer support to obtain correct ballistic solutions.
On the Discovery Channel TV show Future Weapons April 9, 2007 episode "Massive Attack" the host Richard Machowicz, a former United States Navy SEAL, made 3 out of 6 shots hit a human sized sheet of metal at a distance of 2,530 yards (2,313 m) at Arco Pass in Idaho.
CheyTac asserts in its Information Paper of 13 November 2006 that "the CheyTac LRRS is a solid anti-personnel system to 2,000 yards (1,830 m). The primary intent of the .408 is as an extreme range anti-personnel system. Groups of 7–9 inches (18–23 cm) at 1,000 yards (914 m), 10 inches (25 cm) at 1500 yards (1372 m) and 15 inches (38 cm) at 2,000 yards (1,829 m) have been consistently obtained.
Groups of 19 inches (48 cm) at 2,100 yards (1,920 m) and 29 inches (74 cm) at 2,400 yards (2,195 m) have also been obtained. All groups that are up to 3,000 yards (2,743 m) are less than 1 minute of angle for vertical dispersion.
The CheyTac Intervention comes in several variants:
- M-200 (29 in (737 mm) barrel length)
- M-200 Carbine (Now out of production)
- M-310 (Single shot and repeater sub-variants all with 29 in (737 mm) barrel length)
- M-325 (Single shot, repeater and tactical sub-variants all with 28 in (711 mm) barrel length)
The main capability differences between the different versions are governed by barrel length which determines the obtainable muzzle velocity. Higher muzzle velocity will extend the effective range of a rifle, everything else being equal. Also, the M-200 and the M-200 Carbine comes with a detachable box magazine and a telescopic stock, whilst the other variants are built on a glass-fiber fixed McMillan stock.
- ^ a b c d e Chey Tac Information Papers
- ^ Chey Tac Information Papers[dead link]
- ^ Kestrel 4000 Pocket Weather Tracker
- ^ Doing MOA capability testing is expensive. This is done by shooting 100 shots, no less than 2 minutes between each shot, correcting for conditions on each shot at 90% of the gun's supersonic range. You count the number of shots within an x MOA diameter. 80% of those shots in an x MOA arc within 90% of supersonic capability gives a REAL MOA value capability for a military grade long range rifle. If 80% of those shots fall within 0.9 MOA, then that is the gun's capability. If humans are shooting the guns, then you should use at least 5 shooters and average the values. Of course, a gun's individual capability should be tested at 200 yards (180 m) to determine if the gun can hold a real group or not. We did this with the .408 in 2001 and 2002. Gives honest numbers, but costs a lot. (statement by Mr. Dean Michaelis, former co-owner and test shooter of CheyTac LLC)
- ^ Statistical notes on rifle group patterns by Robert E. Wheeler
- ^ CheyTac retail price list for civilian products[dead link]
- ^ Meter, Sebastian. "GROM Utility and Equipment" (in Polish). Gdansk House Publishing. http://grom.mil.pl/uzbrojenie_pliki/UZBROJENIE.HTM. Retrieved 2009-08-02.
- ^ YouTube video about the Bordo Bereliler (Maroon Berets) showing a CheyTac Intervention rifle at about 3:40 (in Turkish)
External images CheyTac M200 CheyTac M200 CheyTac Intervention M200 with suppressor CheyTac Intervention M200 Carbine with Simrad KN203FAB Mk IV night sight mounted
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