You didn't say what caliber or type, seems everyone is assuming you're shooting milsurp. I have used some Hirtenberger 7x57R in my Merkel combination gun. It shot well, and was loaded with good bullets - Nosler Partitions. It was Berdan primed though, and also had some kind of asphalt cement between the bullet and neck, a black tar-like stuff. The tar didn't seem to affect accuracy, but I didn't like the idea of the bullet dragging some of it down the bore.