Jim explains: << All other things being equal, a smaller knuckle would require a higher capstan to get the same hammer line,.... but since we only changed the roller/knuckle the key must move further to reach letoff and it is this addtional key travel that produces a higher catch point for the backcheck. >> Oh, ok, if you change the knuckle and don't reregulate, then the difference will extend to virtually everything. However, if you decrease the knuckle size, and re-regulate the action's hammerline, let-off, drop, and spring if it needs it, I don't see the difference in diameter changing the backchecking. Regards, Ed Foote
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