Then by that logic, LRB's in classics wouldn't work either and neither would the rifling of barrels for guns that used round bullets.
http://www.youtube.com/watch?v=wGgnCEOslZM
Hitting a target 77m away with a gun shooting ~210FPS with .28's... Shooting at a target 175 feet away with my HK416 shooting 327FPS (on a stock barrel and bucking, I put in a madbull bucking and a 363mm lonex tightbore for this test because it shoots farther and faster with them in) only a couple shots in a burst of about 30 rounds would hit the target, and I had to aim high and arc the bb's. The same barrel/hopup/bucking in my M4 shooting 440 can hit the target pretty easily, though.
Edit: The G-hop is a less effective but easier to install version of the R/ER, basically.