Mosins have safeties. You pull back the "ring" at the end of the receiver and turn to the side. Pull back and center, and the safety is off. It's stiff, but a safety nonetheless. I used to take an M38 with a scout scope hunting. I'd use the safety while hiking until I got into the field.
Safety off at the left; safety on at the right.
True, but I don’t believe the safety was used often in the field of battle, as that extra second to release it was the difference between life and death.
I don’t use it, myself, but I don’t carry it loaded until ready to knock a few rounds out.