LOW - I have heard of that many more times than I wish I had.
Rule number one - always point the muzzle in a safe diretion. That way iffen anything stupid does happen, at least no one gets hurt.
Rule number 2, keep your fioger off the trigger. That should also mean off the lock of a ML as well.
Rule number three - check to see that the gun is unloaded. One can always use a rod to check the barrel and see if the rod goes all the way to the breech.
I just unloaded my old Scoumaters rifle. It had held a powder, patch and ball for nearly two years. He actually thought he had doubled cherged it. Then forgat about it and was scared to try anything.
I lubed it with Brake Free and pulled the ball. The patch at powder came with a little coaxing. Only one load!
The barell came clean with a good scrubbing and seems to have no ill affects. The lands and grooves looked clean in my bore light.