User blog comment:Cod1/U.S. Marines with AK-47s/@comment-1790643-20100410192352

There is no trade-off between accuracy and power. The Kalashnikov trades accuracy for reliability. With power, your potential rate of fire drops off because you have to compensate for more recoil, it has no effect on accuracy if you can control it. The AK's problem is that it doesn't always shoot straight because there's more give in the parts.

Soviet 7.62 x 39mm != 7.62 x 51 NATO.

7.62 NATO is a full-size rifle cartridge, and packs much more of a punch than either 5.56 NATO or 7.62 Soviet ammunition because those are smaller intermediate (between pistol and rifle) cartridges.

The 7.62 NATO cartridge has a longer case and bullet than 7.62 Soviet, and contains more propellant, so it travels faster and hits harder and has a longer effective range.

7.62 Soviet has a shorter case with less propellant, a smaller, short, fat bullet that doesn't travel as fast and isn't as aerodynamic as the two NATO types, so it has trouble penetrating armour, has a shorter effective range and is less likely to tumble in flesh, meaning it's less lethal.

Calibre is not a direct indicator of stopping power - it's just an indication of how wide the bullet is. Other things like the size and length of the bullet, the case and the shape and composition of the bullet, as well as barrel length determine stopping power. I'll say again, the AK-47 cartridge doesn't generally have more stopping power than a 5.56 NATO, despite the larger calibre.

/rant.