Nato_Republic said:
Um, recoil and muzzle rise are problems on AR-15's? I have built 2 and fired many, never had a problem with either on a 5.56 rifle.
Recoil, not so much due to the buffer/ spring assy. But muzzle rise is an issue when firing multiple shots rapidly. A decent compensator will direct gases upward thereby forcing the muzzle downward slightly in an effort to help compensate for the movement.
Is it necessary? Well, that all depends on what conditions you are shooting under. Killing coffee cans in the sand pits probably won't require much in this regard. Trying to lay down a good, accurate base of fire for protective purposes is another story. As well, people who are desiring every little benefit toward winning matches would definitely need every advantage they can think of.