Most often the coning is done by the buyer, or the buyer has it done by someone else. Either way the quality of the work is out of the makers hands and controls. If the barrel for some reason does not perform as expected, the buyer may blame the maker, when the problem could be a poor job of cone work. Unless there is a visible fault in the bore of the barrel, the maker would have to take time out to try and find if the problem is the barrel/makers fault, or the cone work. If it were the cone work, the customer may not believe the maker, thus causing hard feelings on both sides, and time lost for the maker. I have heard of few to no complaints from those who have their barrels coned, but I don't see many if any serious target competitors using coned muzzles. I don't shoot competition, but that tells me that I don't want it. To each his own.
