6.5 mm grendel
| 6.5 mm grendel | |
|---|---|
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| general information | |
| caliber | 6.5 x 39 mm |
| Sleeve shape | Bottle neck sleeve, rimless with pull-out groove |
| Dimensions | |
| Sleeve shoulder ⌀ | 10.87 mm |
| Sleeve neck ⌀ | 7.44 mm |
| Floor ⌀ | 6.5 mm |
| Cartridge bottom ⌀ | 11.15 mm |
| Sleeve length | 38.7 mm |
| Cartridge length | 57.5 mm |
| Weights | |
| Bullet weight | 7 g |
| Technical specifications | |
| Speed v 0 | 850 m / s |
| Bullet energy E 0 | 2530 y |
| Lists on the subject | |
The 6.5 mm Grendel is a medium cartridge that was developed by Bill Alexander and Arne Brennan in 2002. The cartridge is a further development by Dr. Lou Palmisano's PPC case that has dominated shooting competitions for over 20 years. The 6.5 Grendel was developed as a low-recoil, precise, long-range cartridge for AR-15 based rifles .
development
The philosophy behind the Grendel was "slower than others at the beginning, faster at the end". High muzzle velocities (v 0 ) accelerate the wear and tear of the rifle barrel and increase the recoil due to the escaping combustion gases, but they only achieve a good top velocity if the projectile is aerodynamically efficient.
By limiting the cartridge length to that of a standard 5.56 mm NATO cartridge (for easier conversion of existing weapon systems) and the premise of firing a much heavier projectile, the Grendel designers chose a short, thick case for a larger amount of powder, while at the same time the case length was saved for the use of long, streamlined projectiles that lose little energy in flight.
While the projectile weight is equivalent to that of an M43 projectile for an AK-47 , the muzzle velocity is considerably lower than that of a 5.56 mm NATO projectile. Due to the heavier projectile, the larger amount of powder and the much better ballistic projectile properties, the Grendel surpasses both model calibers by far.
| Bullet type | Muzzle velocity (m / s) | Speed after 1000 m (m / s) |
|---|---|---|
| Lapua Scenar, 6.99 g | 820 | 355 |
| Lapua Scenar, 7.97 g | 793 | 372 |
| Lapua FMJBT, 9.33 g | 750 | 370 |
Advantages and disadvantages
Speed
The Grendel bullet has a high level of speed and only slowly loses speed over the relatively large distance of 1000 meters for assault rifles . As a result, the trajectory is longer than with other calibers, which have a higher muzzle velocity, but lose speed more quickly and drop well below 1000 m into the subsonic range. Thus, the Grendel makes aiming easier, as the shooter does not have to estimate the distance so precisely and can still work over relatively large ranges with a single stopping point.
precision
The long, heavy and well-shaped bullet ensures a very stable flight position. Light bullets such as B. 5.56 × 45 mm NATO or 5.45 × 39 mm can stagger during the flight for various reasons, z. B. when falling below a certain speed (due to the projectile shape) or when contact with obstacles such as leaves or branches. The stable flight position of the Grendel, on the other hand, enables shots to be fired without loss of precision due to tumbling.
Target effect
Calibers like 5.56 mm NATO offer reasonably good flight characteristics, but the penetration power is rather low. Soft targets are not switched off as reliably at a distance by hits as e.g. B. by 7.62 × 51 mm NATO . Due to its high weight and high speed, the Grendel projectile promises a good energy release in the target, and thus a similarly good effect as the 7.62 mm NATO even at great distances.
restrictions
Due to the conscious decision to keep the cartridge as long as the 5.56 mm NATO, existing weapons such as the M16 or G36 would be relatively easy to convert to the new caliber. Nevertheless, millions of rifles would have to be modified or newly acquired within NATO alone , which would be difficult to convey in view of the limited defense budget of many member states. In the case of rifles with built-in target optics such as the G36, these would also have to be replaced, as they are matched to the flight characteristics of the previous caliber.
Due to the 11 mm wide cartridge base, the ammunition supply is limited. Typical 5.56mm NATO assault rifles have a capacity of 30 rounds per magazine. A similarly sized magazine for the 6.5 mm Grendel only holds 26 cartridges.
Due to the high amount of powder and the resulting muzzle energy of ~ 2500 J, the recoil is stronger than with the 5.56 mm, but still more controllable than with the 7.62 mm NATO. In fact, this is particularly relevant for bursts of fire.
See also
- 6.8 mm Remington SPC
- .277 Wolverine (6.8 × 39mm)
literature
- David M. Fortier: The 6.5 mm Grendel from Alexander Arms , The Small Arms Review, Vol. 8, No. 6, March 2005, pages 25 to 27 ([The HK36 Early ACR Candidate, Cal. 4.6 × 36 mm can be viewed online in the web archive])
- Stanley C. Crist: Small Arms Ammunition for the 21st Century: Hight-Performance Alternatives to the 5.56 NATO Round , Infantry , May – June 2006, pages 28 to 31 ( available online ; PDF file; 209 kB)
