Space Marines are the quintessential figures of 40k. I basically play Dark Heresy with 40k rules.

How badly did I suck? I managed to jam my gun once 3 hours into the game, misses 5 shots out of 6 in a combat stage, failed to dodge 6 times out of 10 and failed to use my silent walk twice out of 4 tries...

Though it wasn't as bad as another guy. He played a Scum and our party was trying to sneak around. All of us rolled an Agility test and passed... except for the Scum who rolled a fumble on a d100 (97).