Over time and a lot of shots, the first strike area of a frizzen gets grooved- how could it not? The flint strikes and cuts steel, scraping down and heating it into virtually incandescent heat. Strike after strike- same deal- sooner or later, they need regrinding and sometimes re-hardening, then tempering to the correct hardness. This has been covered here many times.
Taylor just re-hardened |& tempered my L.C.Rice tuned lock's (Durs Egg) frizzen and the sparks glow & buzz right to the floor - that is, the ones that miss the pan. The sparks hitting the pan, sizzle and buzz around in the pan. Ignition is very good - btw - much better than when that lock was new.