Ive got a CVA buckhorn thats rated to 150gr. I dont intend on goin past 120gr if that.

Anyway my question is, with it being rated to 150gr would it be safe to shoot the heavier bullets (400gr+) in it with powder charges up to 120gr? Im thinkin 100gr of pyrodex and a 430gr lead maxi-hunter this year.
Spike bucks come with their own meat skewers.

Alright, I'm here now who wants my autograph??