The human body is underlaid with this pesky thing called a skeleton, which means through-and-through/in-and-out wounds (which are generally the worst bleeders) are rarer than Hollywood would have us believe. More often a bullet bangs into a bone and lodges, or goes on a ricochet tour of your insides. Unless that bullet also ruptures an artery, there's not going to be gallons of claret everywhere, even from an intermediate-power round like the AK's 7.62 x 39mm.
As for the headshot, thats another one where the bullet is more likely to stir your brain pudding than punch through two thick plates of bone, and won't bleed excessively.