As far as I know, Red Orchestra doesn't use hitscan for any of its weapons (there's a fairly robust ballistics system, with bullet drop, etc). The SMGs are only effective in close quarters, at long ranges their accuracy and range is abysmal.
The Semi-auto rifles are better at longer ranges and can fire more rounds than the bolt-actions without having to reload, but they have a fair amount of recoil and muzzle climb.
The bolt-action rifles (including the scoped Sniper variant) have the highest range and are the best at fighting at a distance. Both the semi-auto and bolt-action types can also fix bayonets, which can help mitigate the sheer power of the SMG at close quarters (SMGs don't get em at all). The game is pretty well balanced among the weapon classes, and as a result all the bolt-action users can keep up with the guys using the high-end weaponry.
At first glance, it does seem rather unbalanced, what with 80% of the players having to use slow firing weapons. But it works darn well, and the game is quite unlike most other shooters