I use Rich Pierce flints exclusively and get AT LEAST 50 shots per flint (and often 75 or so) using lead rather than leather to hold my flints "solidly" and by keeping the flints "sharp" by using a file to sharpen them without removing them from the jaws of the cock.
By using lead to hold my flints, I can easily and very securely move the flint out further in the jaws as the "nose" of the flint wears down.
I start out placing the flint as far back in the cock's jaws as I can and then, by slowly moving the flint "out" toward the front of the cock's "jaws" as it wears down and keeping the flint's "nose" sharp (with the file), I am convinced I'm increasing the "life" of the flints.
I keep a diamond-impregnated file in my shooting box to very quickly sharpen the nose of the flint whenever it seems to be getting too dull.
I've even turned some of my flints side-ways, quickly sharpen the leading edge with the diamond file and have gotten another 10 or 15 shots with a well-worn flint because I can very securely hold the flint in ANY position in the cock's jaws with the lead which tends to take a solid "set" on the uneven surfaces of the flints and will "hold" the flints very securely... even with only a very small part of the flint in the cock's jaws... something I doubt that leather could do.
Occasionally, I've had a few flints crack or split... but I think that is caused more by a flaw in a particular flint than anything I'm doing to it.
I think most of us have had the same thing happen to an "occasional" flint, but... regardless, I'd be unhappy if I didn't get AT LEAST 60-70 shots (or more) out of a flint.
Anyway... this has been my experience with flints and it "works-for-me".
You can get a whole set (8 or 10) diamond-imbedded files at Harbor Freight for about $10... or slightly less and they seem to work just fine.
I hope this information helps you to increase the number of shots you get from your flints... and if you're not using Rich Pierce's flints, you might give them a "try"... Rich's prices are VERY reasonable and I can find NOTHING wrong with his flints.
One more thing you might consider... I had my black powder gunsmith LIGHTEN the cock's spring on my flintlock rifle... it seems to me that a great many "factory-made" rifles have too strong a cock-spring... much stronger than necessary to get-the-job-done.
You might consider looking into lightening your cock's spring a bit... that tends to lessen the chipping off of the nose of the flints thus increasing flint-life.
Make GOOD smoke... :thumbsup:
Strength & Honor...
Ron T.