Bad habit to have at some ranges. Will get you tossed for a safety violation.
As far as a sear or tumbler notch failures, I have see a number of them. Always a few minutes of disbelief when it happens, usually at an unexpected and odd moment. There is a discussion right now in the percussion sub forum on a failed sear.
Broken sear nose-.50 cal T/C Hawken
Interesting you mentioned you have a Pedersoli. I have a Pedersoli that when knew had an issue similar to what
@Bob McBride mentioned. Not enough wood was removed from the mortise and it interfered with the lock to point that the sear wouldn’t catch or stay engaged when you bumped the stock.
And as long as you are into being historically correct, have seen a reference from a military manual instructing the soldiers to place a number of lead balls in the mouths for quicker reloading. Just had to place their mouth over the bore..... you should probably practice with only one or two balls first.