Guns, Dogs and Blades QnA

Why not 357 max?
So I compete in what is called the Buckhorn Challenge, it is a side match in Cowboy Action shooting. Yours truly is last years Champion. The caliber must be period correct, thus the 38-55. I won last year with a 38 but now I got a big ole X on my back so figured I better up my game a bit! I am at a severe ballistic disadvantage shooting plain 38s against the big boys. And make no mistake they will be gunning for me this upcoming season. No quarter given. Short answer 357 Max did not exist in 1870s!