You ACTUALLY want 15 inch arms, because that is how big Sly's guns are.
That was one of the slight variations I am speaking of.
Also a little more shoulders and slightly thicker chest.
I can't believe his arms are 15 inches though. I would say
16 at least. The biggest mine have been were 17 cut
and that was as big as I wanted for my frame.
Stallone didn't have hardly any bicep peak either which
would be another variation.