Actually, the M14 (or Springfield M1A, in some cases) is making a comeback because of it's accuracy (since it's basically a M1 Garand chambered in 7.62 mm NATO instead of 30-06 Springfield and is capable of accepting detachable magazines) and easy use as a Designated Marksman Rifle (although it's being circulated out in favor of the lighter, more accurate SAM-R and SPR).
Also, please don't confuse
stopping power with
penetration power (BOW CHICKA BOW WOW). The 5.56 mm NATO is fairly weak when it comes to penetration, but it has PLENTY of stopping power. Because of the bullet's low caliber and high muzzle velocity, it has a tendency to bend and shatter when entering soft targets (like a human body). All these tiny pieces of metal are
almost guaranteed to **** up a vital organ (assuming that it was a torso-shot, which isn't really a problem for a U.S. Marine capable of hitting a man-sized target at 500 yards), which is enough to bring (and keep) down even the most ardent "target" with shitloads of muscle relaxant drugs circulating through his/her system.
Ridiculously bored, so felt like sharing all of that with y'all.