First of all that's not 315. The cambered bar is 25 pounds, so he is really lifting 295 and yes its real. Ronnie's triceps are bigger than your head.
when your putting 295 behind your neck like that,, it would be impossible to keep your feet on the floor.. thats like doing a pullover lengthwise on a flat bench with nothing to hold down your legs
he's moving the wieght way tooo slow and full range of motion both of which are not ronnie coleman trademarks he usually just throws that sh^t around