I remember reading, years ago, of a man around Tulsa OK who opened his truck door and out fell his old model .44 mag Ruger. It landed on the hammer and Boom. DOA.
I believe it was this incident that caused Ruger to redesign their revolvers and offer a free conversion for the others.
On article at the time said you could load six if you placed the hammer firing pin between two cartridges in the cylinder. I tried this and it did not work with the .45 Colt.
It works with a replica Remington 1858 New Army Model .44 cap and ball revolver. There’s a notch between each pair of chambers where you can rest a spur on the hammer to prevent discharges from accidental drops, accidental cylinder rotation, and accidental trigger pulling. Look for that with any metallic cartridge revolver. If that’s not present, there ‘s a feature on most S&W revolvers where the hammer backs off, preventing any accidental discharge, as soon as the shooter releases the trigger.