Third Generation Battle Rifle

[SHORT-N-SASSY]

I can't find it either, except for this: http://www.chacha.com/question/what-is-t...5a1-bullet:rolleyes::confused::eek:

"A 62 gr M855A1 bullet has a Ballistic Coefficient: 0.371. Initial Velocity: 2970 fps."

Needless to say, an anonymous unattributed answer on "Cha-Cha" isn't anything I'd cite anywhere.LOL:o

Among the results from a subsequent search for more detailed information on the new, improved M855A1:

1, M855A1 - ShootersCalculator.com --- "Bullet Weight, 62 grains; Ballistic Coefficient, 0.371; Initial Velocity, 2970 fps."

2, M855A1: Should it be the New Round for Soldiers and Marines? Guns & Ammo, March 7, 2012 --- ". . . It shoots flatter. Of course the reason it shoots flatter is because they've juiced the round up so that it will fly at 3,100 fps. This would be a great achievement except for the fact that they did it by increasing the chamber pressure from 55,000 psi to 63,000 psi. That's a number closely approaching proof-load pressures. . . ."

3, An Army Outgunned - Physics Demands A New Basic Combat Weapon, By Joseph P. Avery, Ph.D, Military Review July-August 2012 --- "America's National Security strategy demands that our combat forces defeat enemy combatants across the full spectrum of battlefield environments, not just leafy jungles or the plains of Europe. Despite an increasing portfolio of enemies that are flexible, well armed, and robust, our Army, Marine Corps, and special operations forces have been stuck for decades hauling assault rifles firing NATO 5.56x45 millimeter (mm) (.223 caliber) varmint rounds over a half-century old. A decade into a new century, we need to adopt a more robust projectile and basic combat weapon (BCW) to meet current and emerging performance requirements. . . . In another attempt to address the significant shortfalls of our current BCW, the Army recently developed the lead-free, M855A1, 5.56mm, 62 gr. Enhanced Performance Round, tipped with a steel arrow penetrator and more powerful propellant *. . . . Ballistic Performance - The physics of external ballistics and current and future combat environments appear to demand a new caliber of weapons --- whether or not based on the M16 chassis. Many firearm experts, combat users, and studies have recommended the heavier and modernized 123 gr., 6.5x39mm Grendel Lapua Scenar cartridge as a replacement for the current 5.56mm NATO and possibly the 7.62mm NATO as well. . . . There is also a possibility that a 6.5mm cartridge, which fits into the 5.56mm magazine, could be 'enhanced' with a steel penetrator and more powerful propellant. That would provide the 123 gr. package with theoretically double the devastation and longer range than the M855A1 Enhanced Performance Round, giving our forces the edge in any combat environment and at any range. . . . A Versatile and Reliable BCW - United States combat forces require a versatile and reliable BCW with the ability to incapacitate the enemy at close quarters, with sufficient ballistic energy to smack-down enemy forces with authoritative force at long distance. We can either analyze the newly developed and currently existing 6.5mm cartridges, or attempt an expensive development of a new family of ammunition. Assessing the recently developed 123 gr. Lapua Scenar 6.5mm, with its high velocity, flat trajectories, and greater knockdown power than the 5.56mm well beyond 600 meters, may be a place to start. The new family of 6.5mm projectiles has over twice the lethality of the 5.56m, M855 NATO round, and regardless of the configuration, with a 123 gr. projectile that does not go subsonic until 1,275 yards, if you can see a target, you can theoretically hit it **. . . . Additional testing is required, and there is always the option of designing an entirely new platform around the current or an enhanced 6.5mm cartridge. It may be prudent to release a group of 6.5mm, M16-chassis weapons for operational field testing in Afghanistan by deployed forces to test against the 5.56mm M855, M855A1 Enhanced Performance Round, and AK47. Research should look into possible enhancement of an even more powerful 6.5mm Enhanced Performance Round, but the enhanced round may not be ideal under all combat conditions. . . ."

All of which prompted me to revisit Bolt Thrust FAQ (http://www.beyond556.com/bboard/showthre...Thrust-FAQ).

* Wikipedia --- M855A1, "The new SMP-842 propellant in the round burns quicker in the shorter M4 carbine barrel, ensuring less muzzle flash and greater muzzle velocity."
** To wit: LRRPF52's recent eye-opening weekend excursion to 1,200 yards, with his trusty 16" 6.5 Grendel and Hornady's 123-grain A-MAX load, aired in these pages.