My chronograph died an ugly death a few years ago when a gas check from my 14" encore in 450 Marlin achieved full penetration of it's face.
HAHAHAHA!
man, with the crazy velocity spreads I was getting with mine, I wish a gas check would have penetrated it!
I have not killed a moose or Brown bear so take it for what it's worth, but If I were you, I would be loading the 300s