As a expansion on the above. A lady was severely injured at the 2012 "Quigely" match at Forsythe, MT. She was shooting a CAST FRAME Ballard that had been lined and converted to 40-65 WCF and was shooting smokeless powder. 40-65 would be a massive overload with BP. The cast frame Marlin/Ballards were never made in a caliber larger than .38 long RF.
This was a gruesome and totally avoidable event. Accident is not a proper term. Shooting a cast frame in a CF caliber is like parking on the RR tracks...

Ballards with cast frames are not suitable for any caliber larger than 22 rf. But there are a lot of Ballards out there that have been assembled from parts perhaps by someone wanting a given model for a collection or to sell.
It is critical that ANYONE shooting an original Ballard check the action. The cast actions are obvious if the breech block is removed. All known cast actions have a 3 line address on the left side. But SOME forged frames do as well.
If its a cast action and is chambered for a CF cartridge its a fake and is not safe to shoot. Period.
Very few gunsmiths know how to properly set up a Ballard action for that matter so some forged frame guns are often faulty in the lockup.
Modern made Ballards are surprisingly strong, for a design of its age. But when Ballard Rifle Co. was at Cody, WY they did not recommend shooting anything but BP in the guns. So if you have a Ballard and shoot it, it is advisable to consider the information above.

Dan