If you'd like to hear of a potentially horrific case of sticking the wrong round into an ancient gun- you can very readily put a .44 magnum into an old Colt conversion from percussion to .44Colt. I know, because I did it into one of mine just to see. I took it out instantly- the thought of it was very sobering when you consider how many of these are out there in functioning condition but lack ammo, and some uneducated person could seek a substitute round. The modern rim is thicker, but some of thes old timers have enough room to make it go. Eeeks!

One of the issues with most Marlin Ballard rifles is the complete absence of a cartridge designation on their barrels! It wasn't until maybe 1883or 84 that Marlin began to stamp the barrels with a cartridge designation. So often new people who buy a Ballard have to try to figure out what fits it, and that can cause huge problems if they're not experienced with checking chambers. I think I might have maybe two out of three dozen original Ballard rifles that have a cartridge stamped on their barrels. And maybe three others that were rebarreled by custom gunsmiths who marked their barrels.