If the MK318 has been optimized for ballistic performance in short barreled rifles, does that mean it has a high powder loading than the M855 and in turn a high chamber pressure?
Flash is a secondary combustion or after burning and in theory has some additional noise, but I have not yet tried to measure it and it is not likely significant. You could shoot with and without a flash suppressor on a system which normally has a lot of flash and listen for the difference.
This is really the part that kills me:
"Having cleared the international legal hurdles over using an "open tipped" ammunition, the USMC..."
I know it's a rhetorical question, but why the hell do we let the 'international community' dictate what Marines and soldiers will be killing the enemy with???!! We're not even signatories to the Hague convention, yet we choose to hamstring ourselves by placating so many countries that always have and always will hate us.
Cluster munitions = Okey dokey
thermobaric = no problemo
claymore = this side toward enemy
buckshot, cannister = fun for all
hollow point bullets = No! No! No! (unless they are open tip and not meant to hurt people)
the propellant was designed to provide optimum performance from a 14 inch barrel carbine. We are getting right around 100 fps higher muzzle velocity from the M4A1 and MK 16 SCAR L than we get with M855. M855 was designed for the M249 SAW which has a 20 inch barrel. It was later adapted for use in M16 (1:7 twist only). You fire a rifle cartridge in a carbine, you loose velocity. You design a cartridge for a carbine, you can gain some velocity back. (some, not all). MK 318 Velocity from a 20 inch barrel is still higher - around 3,025 fps.
As far as charge weights, both M855 and MK 318 are very close (full case capacity). They do not use the same propellant. M855 propellant was designed in the late 70's. MK 318 propellant was designed for the MK 318, and actually the MK 319 (7.62mm SOST big brother).
I've had a limited amount of time to work with the new ammunition, but I have shot both 5.56mm (62gr) and 7.62mm (130gr) variants. Haven't had the opportunity to observe its effectiveness first hand (thank God), but from people I know "down range" at the pointy end of the"Tip of the Spear," it works like gangbusters.
We're switching over from Mk262, which, IMHO, is a BIG improvement over the M855, but is still somewhat velocity dependent for best performance. Since we nearly always have our CQB barrels installed on our Mk16s, we're very happy about this new ammunition design, since it's not supposed to be as velocity sensitive for optimum performance.
We've had 0 reliability issues, and it does seem to be "cleaner" than Mk262, which, IMHO, is the dirtiest military-issued ammunition I've ever shot. Accuracy is more than acceptable - we use a 50m zero on our CQB barrels, and, from an expedient rest in the prone, everyone on my team was able to hold quarter-sized three shot groups with minimal effort. It's not quite as accurate as Mk262, with which I've shot several dime-sized three shot groups at 100m, but it seems markedly more accurate than M855 (with which a quarter-sized zeroing group at 25 meters is considered acceptable).
I was interested to see that the bullet design uses "driving bands" instead of traditional bullet-to-bore contact - that may be part of the reason for its accuracy and increased velocity.
Regards,
Kevin
Last edited by kjdoski; 02-28-10 at 13:13.
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