These guns were all made for fiber wads and modern wads make them shoot very tight, and sometimes "blown", patterns. It is not at all uncommon, on "using" guns, to have the chokes altered, chambers lengthened, and less often-barrels shortened. In my often disregarded opinion, unless you expect to make a lot of money selling this gun, you are better off with this gun than one that is "right". It doesn't make sense to pay a premium for an unaltered gun and then alter it to make it useable. My advice is to square the muzzle up ,polish it( the muzzles of new German guns were usually "bright" anyway) and use it as long as your legs allow you to follow a bird dog. BTY "choke" is designated by a percentage of shot in the pattern, and the common gage cannot measure this.
Mike
