I tend to think the opposite. It's my opinion that the whole 5 only load never existed in the old west. I believe it's a Hollywood construct. Heck, people still call it the John Wayne load. I have to imagine that if the majority of cowboys were loading only five, Colt would have made their cylinders hold five only and not bothered to bore out an extra one. Colt also built in a safety notch, while not the safest way to carry a colt, it speaks volumes about how many were supposed to be loaded. I have never read anything in history where cowboys were only loading five, but I have read many times where cap and ball revolvers were not only loaded and capped with six, but troops carried extra loaded and capped cylinders on them for easy reloading, sometimes with ill fated results. I know that if I were a cowboy in the old west, I would be carrying six because the odds of setting off a loaded round while in the holster would be far smaller while fighting Indians than the need for that extra loaded round. It is called a six shooter after all.