There's not a thing wrong with those muzzles. The chamfering is correct, and the polish marks look just right. The black marks are discoloration from firing - powder residue and nothing more.

Merkel has the practice of leaving the barrel wedge prominent. The finisher used a flat hone to polish the face of the muzzles. He first polished horizontally above and below the square wedge. Then he polished vertically to the left and to the right of the wedge. So in the final finish you will see vertical polish marks to the left and right with horizontal polish marks above and below the wedge. All are defined by the width and height of the prominent wedge.

The black marks will clean off with a bit of solvent and judicious rubbing.

To make you feel a little better I just pulled out the barrels to my Merkel .500NE. They are exactly the same, even to the point of having some powder residue. I know that mine has not been altered in any way, since I bought the rifle brand new.

A Merkel is a very well-made and serviceable rifle. They fit and handle well. They represent very good value in today's market.

Curl