You don’t see many people carry .32 ACP pistols any more. But KelTec still offers their ultra-easy carry little P32 mouse gun. While John packs his in a comfortable DeSantis Sof-Tuck, that’s a gun that’s just as much at home riding in a front pocket (in a pocket holster, of course).
Plus, the little gun leaves sheepdog John plenty of room to tote an extra mag, a light and a good blade.
As for caliber, plenty of people deride the .32 as too small with too little stopping power. But if the choice is carrying a .32 or not carrying at all, the .32 ACP will certainly make an impression on any would-be attacker.