A comparison of 7.62x39 vs 5.56 - let's look at how the rounds stack up ballistically and what each offers over the other for shooters.
Russia's Greatest Round: 7.62x39 - Guns and Ammo
Examples of modern military rifle cartridges: 7.62 mm NATO (left), 5.56
Noobie guide to 5.56 AR rifle ammunition. – Matt's Homepage
5.56x45 vs 7.62x39 - Cartridge Comparison - Sniper Country
Does the 7.62x39mm has better stopping power than the 5.56 in FMJ format? I have heard that the 5.56 round actually does more damage, because of its tendency to yaw and fragment
7.62x51 vs 7.62x39 - What's a Better Rifle Round?
223 vs. 5.56 - What's the Difference? - The Broad Side
5.45x39 VS 7.62x39 - Wideners Shooting, Hunting & Gun Blog
Spec Ops Doctor: Rather Shot With AK-47 over M16 -The Firearm Blog
What's the difference between 7.62x39 and 5.56x45? - Quora