Thats correct. The AR-10 is based off of the 308 and the ar-15 is based off of the 5.56/223. Two different legnths of actions. The 5.56/223 and others that fit the ar-15 are considered a micro length or supershort action. The 308 is considered a short/standard action. It has to have a longer bolt throw to eject the brass.
Look I like glocks. I've owned Sig's, HK's, 1911's, S&W, and other fine pistols but Glocks have been a favorite for me. Handguns without safeties are not dangerous. Idiots are dangerous.