Dennis,
I could see someone flattening one rifle ball to make a flint wrap in a tough or emergency case, but two lead wraps sort of suggests the original owner was using them commonly.
Virtually all my experience with lead wrapped flints has been with repro military muskets in reenacting and some folks used them on original flintlock muskets on the US International Muzzleloading Team. Reenactors often fire their “firelocks” MANY more times each season than even many/most dedicated target shooters. It is not uncommon to fire 60 to 80 blanks in a reenactment, though that is far more than was ever shot in most original battles. It just makes a better “show” for the crowd.
The lower quality (than original) repro locks should have shown many signs of damage with lead wraps, had that been a significant problem. Now I’m not saying some cocks did not crack or warp, but it did not seem to be a significant problem and I’m not sure it can be directly related to using flint wraps as opposed to lower lock part quality.
However, I personally never used lead flint wraps in either my vintage 1976 Pedersoli Brown Bess Carbine that I used to compete in Northwest Trade Gun Matches and reenact, nor my 1997 full size Pedersoli Brown Bess Musket I reenacted with. I got better sparking and at least I believe I got longer flint life without reknapping by using leather wraps.
Now it could also be using different thicknesses of leather allowed me to better adjust the strike of the flint on the steel. I also know that some reenactors used flints that are really too big for their locks. Don’t know how many times some reenactors used original French flints that were oversize for their locks and I had to explain that and get them to use flints suitable in size for their locks. Usually when members of my reenacting unit gave me their muskets to work on, I would find the correct size flint and leather and their locks sparked correctly and for longer periods. In some cases and with guys who had reenacted for years, they told me their locks had never sparked and worked so well and for so long. We also have to keep in mind that a good number of Reenactors with Flint Muskets rarely, if ever fired a live round with their muskets, so they didn’t know as much about working their locks.
The US Military issued lead wraps or flattened musket balls for flint wraps all through the flintlock musket era from the Revolution to the last Flintlock Musket Model 1840. Had lead flint wraps been really damaging, one would think they would have changed that? MAYBE it was the size of the cocks in those locks that could just take more stress without serious damage?
However, as Habu noted above, I think the added weight of the lead wraps could/would cause MUCH more noticeable stress and damage on smaller cocks especially those that have thinner metal “between the lower jaw and the "breast" of the goose” as Habu noted. I am not an mechanical engineer, though, and don’t know how to calculate the increased force of the cock and flint hitting the steel with a lead wrap vs a flint wrap.
Side note to Habu,
Please don’t take this as anything personal, but I cringe when I see your Avatar or type it out. One morning in 1972 around 0600 just when there was some light and I was on my way to opening my Armory on Okinawa, I got chased by a real Habu for quite a distance. Even though he was in a shadow, Thank God there was enough light to see him else I may have walked too close to him. I set a personal speed record running from him that morning. I STILL shudder when I think back on it.
Gus