There's nothing wrong with Pieper guns. He was well known for his fine Damascus barrels. At a Worlds Fair he submitted a set of Damascus barrels with his name in them over and over down the length of the barrels. It won first place.
We have a member here who discovered that underneath his blued barrels were a set of Damascus barrels with Pieper's name repeating in the pattern.
Henri Pieper was also a co-founder and original managing partner of FN, which I believe is now the world's largest maker of sporting arms and an integral part of the success of Browning.