Telling them about the damage system doesn't help much, since many don't understand anyway.
The problem is that we have a decade of UT, Quake, Counterstrike, and Pretty Cool Guy where fatalities happen whenever you hold the trigger down and look near someone for no more than 2000ms with almost any weapon. Shoot more always makes up for aim more in those games.
There are no games in the market that I know of that punish bad hits with good guns enough that good hits with bad guns, so it is a foreign experience for someone to get RC-P90, spam 40 rounds into someone with armor, and then see that player run away with said RC-P after delivering two shots to the head with a sighted PP7.
Badgering noobs with technial details won't help -- if they're interested they'll ask or surf the wiki. What we need is to ensure we are delivering an experience so awesome that players will enjoy it even when losing* so they will play long enough to get the feel of the game. I'm thinking more "negative" achievements (like how TF2's Sniper has an achievement for being shanked) to keep players feeling like they're doing something even when they're failing it.
* This is a cultural problem. In 007, you played with your friends and you couldn't just hop to a new game that had shittier players when you weren't the big fish. You had to keep trying to win that one glorious round where you managed to establish and control the top weapon and armor.
Thus, we must encourage players to form groups. Small groups, up to five, that play together in DM and against each other in teamplay scenarios, on a regular basis. We need a few dozen mini-clans that can insta-seed servers.
