he close grips 440 and his tri's are still small. idk why skull crushing would mean all the sudden he'd start growing.
Is mr. friendly actually asking me a question? This is the same scenario as previously discussed many times and should be obvious by now. Low reps especially with compounds don't necessarily lead to arm size, like most weight and power lifters. Anyone who develops strength on non-compound BB exercises that hit the muscles squarely and more intensely and uses moderate reps will see the muscles grow. You won't find many guys doing 150-200 lb. preachers or extensions for reps with small arms. Same with flys.
In the mid-70s as a kid i was lucky enough to live in the West Indies, which has the highest percentage of great BBs and sprinters on the planet. Oliva, Dillet, Fox, Nubret, Al Beckles, Callendar, Rick Wayne, Stubbs all from the West Indies. I was able to go to the same local gym in in Barbados as some of the top guys including Al Beckles cousin Darcy Beckles, who placed in the Universe a few times. I remember him doing 130 lb. preachers with good form, under control for reps-20" cut arms pumped on a small frame-small wrists, 27" waist.