I usually warm up with 35-40's and walk my way up to 65-75 for 6-8 reps.
I rarelly see anyone go over 40... Tapoutters in the 20's...
All big delts, big cock and alpha attitude
take a look at the size of the medial delt.
alot of weight isn't need to stimulate it.
you know your own body better than anyone else does, but i would bet you'd get the same if not better results by going lighter.
take a dumbbell and stand with it like you would be doing standing one arm side laterals. start the motion with the dumbbell
behind your back. now raise it up keeping your elbow on the same plane or slightly higher than your hand during the movement without using momentum. that'll be a good starting point to gauge just how much poundage you could use most effectively.