The range and effectiveness of today's buckshot has certainly changed!
The "sea change" in buckshot ammunition is no different than what has happened in the field of shotgun "slug" ammunition. There are many states and govt. managed lands that require the use of shotgun slugs. This was instituted in the era of the Foster style slug that were and are very limited in range. However, Remington, Winchester and Federal have all thrown "long established industry standards" to the wind. Today's shotgun slugs (abeit in rifled barrels) have a greater danger range as current factory .45-70 and .444 ammunition, let alone the .44 magnum carbine. Virtually all state wildlife agencies that restrict hunters to shotgun slugs have not changed their regulations but simply accepted the new reality.