I agree INFANTRYMAN,Im a bushmaster guy myself,I like rock river the quality is excellent except for barrels,The bushy is mil spec 4150 stel MP inspected,under normal use the steel quality is not a factor but for a field rifle the better steel performs better under the strain of rapid fire and hard use,So if I could get a RRA cheap I would but id still have to put a bushmaster barel on it.As far as barrels I perfer the heavy,ive got one on my pre and postban,I dont care much for the M4 profile so my carbine with a mag in gives the same weight as a full size,roughly a pound more,besides the M4A1 just go a heavier profile barrel to make it more reliable so heat wont make the barrel fail the way the lighter one has,maybe when they start ataching the M203 a different way they will use the more reliable especially for full auto fire HBAR.