So I went to look at the Merkel I have and there is no discernible chamfer on the outside edge of the barrels at the muzzle. It is very square and almost what one might call "sharp". There is a small chamfer on the inside of the bore as one would expect where the crown was finished at the factory. Mine is a 9.3 x 74R, but I expect that factory finishes at the muzzle would be much the same irrespective of bore. My other doubles of recent manufacture show similar traits, but the Heyms have a tiny bit more pronounced internal crown chamfer. The external edges of the muzzle display the same squared off trait as the Merkel with no discernible chamfer. Hope this helps......