Hello, My 12 year old, average build son wants to learn to build a Kentucky pistol. I have much modern pistol experience, but no flintlock pistol knowledge. He and his older brother will be shooting .54 rifles when we get them done, and for the sake of uniformity I was thinking the pistol could be a .54 as well. Would that be too much recoil? Would you go smaller, and if so how small? Thank you, James