Don’t underestimate the danger in a big lock like this. Many years ago a friend and I took advantage of a sale of some replicas of the 1763 Charleville musket locks. They were from the musket replica made in Japan. The locks arrived and we both separately decided to test them, to see if the frizzen was any good. These locks were as manufactured, and not tuned at all. I tried to cock the lock, and found it very difficult without it being in a stock. When I tripped it the powerful spring almost made it jump out of my hands. I thought I probably should warn my friend about the powerful spring, and the shocking amount of sparks the lock produced, so I phoned him. His wife answered, and when I told her why I called, she told me I was too late, he had already partially severed one of his fingers when the lock tripped while he was cocking it.
Even after tuning, and polishing, this lock is very powerful. I have worked with many Bess locks, and trade gun locks, but none of them are as powerful as this lock. So I suspect the lock you have could demonstrate some of the same characteristics.
Hungry Horse