That old steel/non-toxic shot stuff can deflect the Buck Shot lead content meter, just as a compass w/o a magnetic deflection will mess up true North in Iron Mountain, MI (or Ironwood, MI- for that matter)--
Lee, all the years (way over 55 now) I have been shooting and hunting, I have never: 1(fired either buckshot or a lead slug through any shotgun), 2(owned or shot anything smaller than a 20 gauge), and 3- dropped a Canada goose in flight stone cold dead at over 45 estimated yards, or have seen it done-- but as they say, and wisely so, never say never.