Hmmmm hadn't thought about that. It could be a pipe he's preparing to beat Magneto with. He definitely seems to be aiming it though. Maybe he wanted Magneto to think it was a bazooka and once that didn't work he gave up on it.
Well, if you look at the end of the pipe, it's not hollow. There's a cover over it. And it looks like angel was winding up to throw it over his shoulder, so Angel was just going to throw it at Magneto or hit him with it.
Remember, this is 1963 folks. Things weren't to sophisticated back then in comics. They probably didn't realize he had control over metal yet and they were just throwing stuff at him to see what would work.