I read the Gun Digest article. The author buys a Holland and Holland Two Inch gun and then proceeds to do everything he can to shoot 11/8 oz loads out of it. He never discusses the guns proofs and his gunsmith agrees to open the chambers 1/8” because there is not enough wall thickness to go the full 1/2”. To me this is a story of how fine guns get ruined over time. The final insult is the loads that he has worked up and shot for a season when finally tested are 50% above saami maximum pressure. The article was published in 1978. Hopefully there is a better understanding now on how to use and enjoy these fine shotguns.