I have a chance to pick up a .450 Marlin H&R from a fellow who realizes it is too much for him. I have no need for a .450 but I do have a .454 Ruger handgun. Can a .450 H&R be rechambered to 454? I have read that the pressure of a 454 is very high. I am not a gunsmith so please excuse my ignorance. Thanks for any advice.