natedog
Member
I believe the listed maximum effective range for the M-16A2 is about 500 yards. I've also heard that the Marines do some shooting with the A2 at 500 yards. How (in?)effective is the cartridge at that range?
I think the rifles to which you refer are SPRs (special purpose rifles). They typically include a true 18" SS barrel with fitted bolt carrier group and a Leupold scope. Sometimes they are suppressed. I have not heard of those rifles requiring more than one shot.I've heard of the guys in Afghanistan and other places doing 500+ yard hits with M4s and M16A2s (scoped, usually ACOGs) on bad guys, and having to hit them 4 or 5 times because at that distance, the round was just poking holes, not tumbling and making a larger wound track.
_BC_ _MV_ 0 100 200 300 400 500 600 700 800 | YARDS
0.243 3120 > -3.43 0.99 0.74 -5.84 -20.79 -47.71 -90.54 -156.31 -250.18 | > 5.56 55gr M193
3116 2725 2366 2033 1733 1467 1251 1095 994 | fps, velocity
0.324 3100 > -3.43 0.81 0.65 -5.04 -17.47 -38.67 -70.50 -116.76 -180.34 | > 5.56 IMI M855 62gr
3097 2802 2525 2262 2019 1790 1582 1397 1242 | fps, velocity
0.496 2551 > -3.41 1.84 0.98 -7.07 -23.29 -49.42 -86.55 -137.53 -203.57 | > 7.62 175gr SMK
2549 2376 2211 2051 1900 1754 1617 1490 1375 | fps, velocity
0.447 2651 > -3.42 1.62 0.91 -6.64 -22.09 -47.27 -83.46 -133.70 -199.57 | > 7.62 168gr SMK
2649 2453 2266 2086 1917 1755 1604 1465 1341 | fps, velocity
0.365 2800 > -3.42 1.36 0.84 -6.25 -21.17 -46.13 -82.94 -135.46 -206.21 | > Hor 6.8mm 18.0"
2797 2551 2318 2096 1889 1693 1517 1358 1227 | fps, velocity
0.395 2700 > -3.42 1.56 0.90 -6.64 -22.29 -48.17 -85.93 -139.20 -210.16 | > 5.56 BH 75
2697 2474 2262 2060 1870 1690 1527 1379 1252 | fps, velocity
Hmm, that's interesting. If i understand correctly, about 2700fps is the magic number where milspec FMJ 5.56 is supposed to tumble on impact. According to that data, the round loses a lot of it's terminal effectiveness anywhere past 100-150 or so yards.Here are some figures based on typical muzzle velocities:
Everyone knows you can buy the 75 and 77gr loadings from Black Hills and Hornady, right. They feel through a magazine fine