Can anyone help me out? I have a SR-762 and been told it's a standard AR10 wrench. I bought one and it's way to big. Then I was told it's the ar15 again wrong. I have call and emailed rugar, and they don't know... What the hell is wrong here? The online support just tells me the don't recommend removing the barrel. Please help.. This is a awesome gun but pretty pissed i can't tear down myself or get any support..