Yea the OP has a point about this...but it pertains more to real world effectiveness as opposed to in-game balancing.
I can't comment about the balance issues, but yea...as far as real world comparison the assault rifles in-game are quite weak
They should be strong out to 300-500 meters, but in-game they're not at all effective at that range as they would be in real life. But this is a video game which must be based upon balancing issues, and not real world performance.
When I want more realistic ballistics in a game which doesn't cater to the PvP balancing act, I goto the Arma franchise.
There is so much that are wrong balancing wise in the game for weapons, vehicles and the lot but i will take the PP29 and M5A3 as a very good example.
Symthic is working on all ingame stats as they did all other BF games and this stats are directly from inside the game.
You guys remember how insane the PP29 was and all the talk about nerfing it and boost some other weapons. Look in first pic below, red is nerf and green is boost. so they actually boosted the PP29 even more, yes they gave it some more recoil but thats not very hard to play with.
Jump to pic 2 where we are today.
PP29, damage start 26, damage stop 18, damage fall off start 30m
M5A3, damage start 22, damage stop 15, damage fall off start 20m
Those stats speaks for them self, seems like some one doing this balancing either have not 1 clue on what he or she is doing or they are really hot on just the PP29 SMG. Like why in the world have they made PP29 - 9mm Makarov pistol rounds to do more damage and have longer damage range than the M5A3 standard assault rifle rounds???. Thinking that way we should maybe put on the close combat mag on the M5A3 and get same good damage and drop off as PP29. When you look more in the tables you will find alot more that makes no sence at all.