Dave, France had a lot of colonies in hot, wet places when Darnes first appeared. And that was one reason for the sliding breech action: not so much the strength of the action, but rather the fact it works better when it comes to the feeding and extraction of somewhat swollen paper shells.
Ted, re honing, I don't think it bothers anyone a whole lot on English guns, as long as the gun is still within proof. That is, not more than .010 oversized for the bore standard. Unless, of course, the barrel walls are extremely thin to start with.
