In the days of 30-inch barrels (and other long barreled military rifles), long range musketry was at least a theoretical option.  Also, there was still horse-mounted cavalry.  In pre-gunpowder days, the infantry had pikes to counter the close-up part of a cavalry charge.  Long rifle barrels and a long bayonet gave the individual infantry soldier a form of close-up defense against both horse & rider.

Winchester & Marlin made a lot of .30-30 carbines with 20 inch barrels.  I don't recall any great furor about muzzle blast when those things were/are shot.