When we hear of shotgun barrels being damaged by steel shot, it isn't because they ruptured due to excessive pressures. Most commonly, the damage results when steel shot is used in older vintage guns that have thinner barrels and tight chokes. The problem is exacerbated when larger shot bridges as it is forced through tighter chokes.
We can minimize the risk of damage from use of steel shot by just not using it in any vintage gun that has thinner barrels and tight chokes, and/or by using smaller shot sizes. A better course of action is to simply not use it at all, because it is a ballistically poor substitute for lead shot.
The best course of action is to fight every attempt by government and game agencies to implement lead shot bans. Virtually all of the lead shot fired over lakes, marshes, and waterways prior to the waterfowl hunting lead shot ban is still there. Some has sunk into silt, but other areas have hard bottoms, or it may be churned up by storms, flooding, etc. Lead shot is still legal in some of the countries where the migratory birds spend part of the year before returning here, so many of the birds are still exposed to it. But the hysteria over ducks and geese dying from lead poisoning stopped right after the anti-lead forces got their way. And coincidentally, there was also a huge reduction in the use of other sources of lead that were much more hazardous and bio-available, such as leaded gasoline, paints, and other chemical compounds.
