RE: Upset with 82nd...
I believe that you need a stiffer than typical shaft for the 82nd. I have my 82nd set at 64# and have the 27.5" mods on. I shoot the carbon express 250's and 350's. I figured out that I can barely shoot the 250's with a 100grn tip due to the fact that I have them cut to 25.75" long, so barely make it. With that said in paper tuning, I found the the 250s and 350s tune about the same, but I have the 350s cut to right around 26". I really believe that the 82nds shoot a stiffer spine better.
Good luck.