Which would make you feel better, watching your son take a buck larger than you ever have, or you taking a larger buck than you ever have?
This is also my sons first year and he gets first whack at anything we see. I may be disappointed to miss out on a giant, but im waaay more excited to see...
Thats a whole lotta bullet for pronghorn.
I would look at the 130 ttsx if your set on a mono bullet.
As far as your load, you can push above max, but do it SLOWLY and keep a sharp eye on brass. Look for bolt sticking at all, any ejector or bolt marks on the base and watch your primers.
I like to...
Keep an eye on hodgdons website. They often have powders in stock. Another option is powder valley. I just picked up a bunch of norma powder. Their urp will put you into the 4350 burn range.