Many people treat the semi-auto rifle as an assault weapon, BUT, do not fall for that trick. You, as long as you have a rifle, you are a rifleman and should act in that way. Pick enemies of at distance quickly, and exploit the 0.5 second reload to give the enemy 2 shots, while he can give you only 1 shot with his bolt-action rifle (except the Americans, who usually use the M1 Cabrine and Garand, although there is the person who chooses the Springfield or M1917 rifle as their main weapon). In close quarters, your long rifle is useless (unless fitted with a bayonet, in the Soviet and American case). Sub-machine gunners are the fist of any assault, except battles that include long distances, while you and the machine gunners are to consolidate the flanks of your group. But in long ranges, the submachine guns are pretty much useless, unless you are the state-of-the-art shooter and end with a lucky kill, and the Riflemen go to work with their long range ability.
P.S Vote for which tutorial I should do next.