I puchased a Bushmaster M4 A3 carbine from a gun shop which I will not mention by name. When I ordered the gun it was suppose to have a Heavy barrel, being new to AR 15's when I recieved it I did not know it was not a heavy barrel. It was not till today that I discovered that it was not after 2 years. My reciept shows it as a heavy barrel and I paid $1285.00 for the gun, which I knew was high because it supposedly had a HBAR. Turns out Bushmaster doesn't make an M4 with a HBAR. What should I do or better yet what would anyone do?