I have a Ruger cap and ball old army, that I would trust, if I had to, And I have left that gun loaded for a year at a time, and it always goes bang, when I decide to shoot it. Plus I have left cap and ball rifles loaded from one year to the next, on occassions when I didn't fire it on the last day of a hunt, and left it loaded. I never remember one not going off, when I finally decided to shoot it. Of course, if the gun has been shot and not cleaned, then I never leave one loaded for any length of time, before shooting it out, and cleaning it. But I have left clean guns, loaded for long periods of time. It's probably not the best practice, but I have not really noticed any ill effect.