Aloha Dugaboy1, I'm very interested in your experiance with the 458 RCBS. If you don't mind me asking what powder, primer, bullet, brass, were you using for your optimum load. What kind of velocity do you estimate you were getting with 400 grain bullets? I see the 458 RCBS brass is 2.75 inches long a stretched 45/70 as you describe it. The 45-110 Sharps/Winchester is also basically a 45/70 case stretched to 2.8 inches. Using modern brass, in your opinion is there any reason why the 45/110 could not be loaded to match the 458 RCBS from identical rifles of equal strength? I was brainstorming doing the same thing you have done to your Kodiak double except chambering to 45/110, and using the more readily available 45/110 brass. What do you think? Thank you for your input.