when shooting steel, choke constriction is certainly a consideration...
plus, one should also consider hardness of steel shot vs hardness of barrel steel...scoring and erosion of bores can occur when steel shot is harder than barrel steel...
Steel shot never gets close to the actual bore. Literally surrounded by an ultra thick, tough plastic/resin wad. There’s no scoring. There’s no scratching. Theres no erosion. The only thing that would cause any of that is foreign elements that were already in the bore (ie dirt, mud, etc). There’s only burnt plastic/resin and powder fouling left in the bore after firing a modern factory loaded steel shot shell.
Again Ed, the shot never comes into contact with the bore.
All factory steel loads are loaded with specially designed wads that eliminates any shot contact. I’ve never seen a factory steel load loaded with a brush wad or a felt wad.
The main issues have already been discussed. High Pressure. Choke constriction. Gun design.
