Tonight while playing Left 4 Dead 2, I noticed something a bit odd. The games textures for its "Desert Rifle" has markings for a MK 17 Mod 3 written on it along with an indicator of it being the 5.56x45mm variant.
That obvious error aside, what makes this odd to me. Just going on instinct from using the weapon in game rather than close look at the models, I would usually call it out as a SCAR or SCAR-H in game. The MK17 is the "Heavy" version firing 7.62x51mm. Someone later pointed out to me, that the magazines are obviously closer to the SCAR-L; the "Light" version of course, being the MK16 using the same 5.56x45mm you'll find on an M16 ;). The games stuff for the SCAR mags to me, look like a curved version of the SCAR-H mag.
Most of Left 4 Deads weapons have double their realistic ammunition capacity or close to it, adjusted for stopping power. Personally, I think that's a flaw but hey, bullets go even faster against zombies! The games SCAR hits more like a MK17 might be expected to, yet the games model appears to have an extended 30-round magazine; L4D does however exagerate the ballistics quite a lot for all the weapons. In game, you get 60 rounds in a SCAR firing on 3-round burst; the old school AR being a 50-round based M16 and the lovely AKM, offering 40 rounds.
3 times the real weapons ammo, can't beat that for shooting through waves of infected! The real odd thing I guess, is how I know just by looking at it, that the gun isn't accurate to real life :-/.