By the time I found Ross (thanks to several posters) and talked to him about the gun, some other gent had stepped up and bought the gun, altough apparently the deal is not quite done yet. Turns out this gun has tapered bores and Ross used to make bumped-up jacketed bullets for it. It shot well with those but not with cast. Somewhere along the way, the bump die got separated. The current owner has never shot it.