so what are the exercises which get you the most arm size and in what rep range?
I've noticed that EZ bar skull crushers have really hammered my Tris. I do 3 x 8 using them.
Weighted Dips 3 x 12 seem to hammer my upper tris and have added some size.
As for my biceps and forearms.. i don't know. They seem to take their time to grow.