06-15-2016, 01:18 PM
(06-15-2016, 12:49 PM)oncemoreuntothejimbreech Wrote: It's not supposed to pass through-and-through because 5.56 causes less cavitation than 7.62, but their have been reports/complaints from Iraq and Afghanistan the rounds are passing through.
Yeah, I had read about through and throughs at close range and small targets.
I can't remember where I read it, but here's the Wikipedia notes.
Quote:An M855 from an M4 has a muzzle velocity of 2,970 ft/s (910 m/s), but that is reduced to 2,522 ft/s (769 m/s) by 150 meters. Even if it impacts at optimum speeds, 70 percent of 5.56 mm bullets will not begin to yaw until 4.7 in (120 mm) of tissue penetration. 15 percent more begin to yaw after that distance, so up to 85 percent of rounds that hit do not start to fragment until nearly 5 in of penetration. Against small statured or thin combatants, the M855 has little chance of yawing before passing through cleanly and leaving a wound cavity no bigger than the bullet itself. The factors of impact angle and velocity, instability distance, and penetration before yaw reduce the round's predictable effectiveness considerably in combat situations.
