Heavy constriction is more effective with fine shot. Large shot sizes are better served by less choke constriction to throw a full choke pattern.
It's no trick at all to achieve full choke patterns from a .015 barrel if you use large plated shot, a target type shotcup, and no more than moderate MV with slowish powders. Polyethylene buffer helps, too. My first Bismuth patterns showed full choke patterns no matter what the constriction. Ditto with steel.
My Beretta trap gun has constrictions of .037 and .043. Marked IM/F. Not obsolete for that application.
Tight barrels are a result of salesmanship and peer pressure. Nobody wanted to have a gun that wouldn't shoot as 'far' as their hunting companion, if he could effectively use the capability or not. Same thing today... note the 3.5" 12 ga.
