I just would like to mention that the bullet won't fly in a straight line and that real guns have various accuracies (MOA), too (but I assume you just took a shortcut here, so mentioning it just for other readers). But it's as you said - it's a game, the muzzle speeds vary, the damage vary and also the accuracy vary from the real-life counterparts. They just took what the gun is in reality and loosely translated it into the game a way that benefits the gameplay, not to be an accurate representation (as it never was in Battlefields).