the S&W 460 mag comes in several barrel lengths. i am interested in the 5 inch and the 8 3/8 inch models. i want the 5 nch model but i am worried about Muzzle Velocity. if i get one i will be using it for hunting sometimes and want as much velocity as i can get. will the extra 3 3/8 inches make enough difference to make it worth it. i know it will make some difference but just how much.