Back2Fronts is an extensive mod that will overhaul your Call of Duty 2 game to a next level. This mod brings more variety, intensity, realism and battle-like experience. Try new weapons, fight new enemies, fulfil new missions and explore new options. Mod is SP and MP friendly (although primary part is SP).
Last group of hand-held weapon's muzzleflashes was edited: FG42 (same style goes for MP44), PTRS (basically enlarged SVT40 flash), MG42 (same style goes for MG34, BAR, 30cal, Bren, ZB26) and finally a DP28. Note that portable MGs emit tracers when firing (green for Russians and yellow for everyone else).
PTRS's huge central flash is followed by 2 side flashes coming from the muzzle brake. PTRS also emits green tracer (not visible on the screenshot).
Green? Is there a historical reason why, or... I've only ever seen tracers as yellow.
yes, Russians used green tracers because their tracer ammo had different compounds in the projectile tip.
here's some reference: En.wikipedia.org
btw both Red Orchestra games (1,2) have that feature too.