I have a .67 smoothbore (9" barrel) I built as a belt pistol for trekking in the woods. Loaded with 1 1/8 oz of #5 shot as a snake deterrent. I installed a brass hook, it rides all day comfortably across the front of my sash.
As for carrying it safely? It's loaded, primed, and set at half-cock.....BUT.....I have a stout form-fitted leather frizzen cover on all the time, attached with a thong. This prevents the flint from making contact with the frizzen in case of an accident. Ya never know when I might drop it or get it snagged on a branch. But its a simple matter to draw the pistol, flip the frizzen cover off with my thumb and cock it in a fluid motion.
I use frizzen covers on all my flinters for the same purpose.
Jack