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Development Notes, Brennan and Alexander Assault Rifle Ammunition, Williams |
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New Developments Could Replace 5.56 and 7.62 NATO AmmunitionNovember 22, 2004 Major Robert E. Berg, U.S. Army Ordnance Officer and aerospace engineer You may have heard that the 5.56 NATO ammo, used by our troops in Somalia, Iraq, and Afghanistan, has not been the best man-stopper. The Soldier Weapons Assessment Team Report 6-03 made the following recommendation: Recommendations: A Government Lethality IPT has been stood up to standardize gel block testing and an engineering study will be conducted extensive, soft target terminal effects of COTS and military 5.56mm ammunition. The characteristics of each bullet terminal performance will be determined. Based on requirements and using the engineering information, a new round should be type classified and made available. In the search for more capable ammunition, two contenders worth considering have emerged from the private sector. Both work with existing M16 lower assemblies (the bottom half of the rifle). Contender #1: The 6.8mm SPC by Remington designed in cooperation with members of military Special Operations Command.
Contender #2: The 6.5 Grendel by Alexander Arms designed in cooperation with Lapua (ammunition manufacturer) and Arne Brennan (competition shooter), and based on the work of Dr. Lou Palmisano (successful ammunition designer).
What are the advantages over current 5.56mm NATO? The first advantage is lethality. The 6.8 SPC has an edge with its current bullet loading over the 6.5 Grendel at short range against unprotected personnel. The 6.5 Grendel has an edge over the 6.8 SPC against light-armor-protected personnel. Both appear to improve upon the 5.56.
Lethality at long range has not been tested. As opposed to short-range engagements with 5.56 ammunition, 7.62 is being used for some long range engagements.
Using ballistics programs on computers, we can compare bullet energy to estimate killing power at longer range. At 600 meters the 6.5 Grendel with 144gr bullet has 831 ft lbs of energy. The 7.62 NATO with 147gr round has 745 ft lbs of energy. The 6.8 SPC with its 115gr round has 440 ft lbs of energy. Finally, the 5.56mm NATO with 77gr round has 308 ft lbs of energy. Advantage goes overwhelmingly to the Grendel at long range. When confronting an enemy approaching in a car, 7.62mm NATO is effective while 5.56 is less than spectacular. At the Blackwater shoot this year, the 6.5 Grendel was tested against armored glass panels. No testing was done for the 6.8 SPC. The 6.5mm Grendel succeeded in penetrating new 1.575Ó VistaSteel armored glass with non-armor piercing ammunition. The Grendel with actual armor-piercing ammunition should be a great performer for that purpose. Ammunition weight and recoil are slight disadvantages over current 5.56mm ammunition The 5.56 ammunition weighs 9.0 lbs per 300 rounds. These new rounds weigh 28% more than 5.56mm. In comparison, 7.62 weighs 53% to 66% more than 5.56. Recoil, with the competitors, is slightly higher than 5.56 and about half that of 7.62 NATO.
Advantages compared to 7.62mm NATO ammunition Comparing the weight and recoil disadvantages to 5.56mm something else becomes apparent. The 6.5 Grendel is delivering similar energy to the 7.62mm NATO yet has a significant advantage in weight and recoil. Based on the militaryÕs original move to 5.56 for weight savings, the 6.5 Grendel appears to be an excellent option to 7.62. I have spoken with Blackhawk and Chinook pilots on the subject of door gunners using the M60 with 7.62 ammunition. I have also fired the M60 from the open rear of a Chinook in Iraq. There is noticeable trajectory change in these rounds. You can watch the tracers arc toward the ground. The change in trajectory is partly due to the long range and partly due to wind effect of rotor wash and forward speed. We agreed that a bullet less susceptible to wind drift and having less long-range drop would have an advantage. Long tracer life is also an advantage as the tracers are the only way to target in this situation. The 6.5 Grendel with its long, high-BC bullets offers all the advantages of longer tracer burn distance, less drop, and less wind drift. Overall Impression Overall, the 6.8 SPC and 6.5 Grendel seem like acceptable substitutes for 5.56mm NATO to increase killing power with slight increase in weight and recoil. A surprising find is the 6.5 Grendel has an advantage over 7.62mm NATO in decreased weight and recoil while retaining long-range energy.
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