I have a 6.5 jap (carcano action) with a 30 and a half inch barrel. I would like to use the action for something but I don't need a goose gun. I was searching the web for ballistic work on the 6.5 grendel and the most barrel seems to be 24 inch max and most efficient 22 inch for powder burn. What do the cast boolit ballisticians say? I might savvy a little european deer stalker rifle, who knows what I might come up with. Depends which way I sit on stump and meditate.