Rick,
Hope you have better luck in your PA Hunter than I have with mine. I've tried several varieties of knapped flints that I purchased at Dixon's fair in both the old T/C lock and the vaunted new design.
Similar result - short life, chipout and shattering. The old lock tended toward short flint life - 15-20 shots total life, knapping every 4-5 shots. The new lock, which was supposed to resolve this problem has consumed 3 knapped flints in a very short period. First flint chipped out - a 1/4" massive chip flew out on the 3rd impact on the frizzen - never even got to the range with that one. 2nd one gave me 12 shots at the range and shattered down to the jaws. 3rd one - another massive chipout after 5 end of day shots during the hunting season. :cursing:
I wondered why T/C shipped it to me with a sawed agate in the jaws - now I know why. Like the old lock, the agate is the only flint I've found so far that does not fail extremely early. :shake:
My hunting buddy gets great performance and good life out of knapped English flints in his Lyman GPR - he was the source of my 3rd failed knapped english flint.
Try the Fuller flints and let me know how you make out please.