Me? A Viper expert? Hah!
My Viper (labeled 40# @ 28") really is 37-1/2# @ 28" and 40# @ 29".
I've been shooting 29" Jazz 1816 XX75 shafts, target points (about 75 grains), 4" feathers. They go fast and straight.
In your case, I'd try 125 grain Wensel Woodsman (to lower the arrow spine - plus, it's a better broadhead IMO
:saywhat: