The CVA and others were likely made of gun barrel steel, which is not expensive.
12L14 steel was used because of its high lead content for easy machinability.
Most people think the soft iron barrels on old guns were much more fragile than barrels made of modern steel and that could certainly be said for proper gun barrel steel. But soft iron is tougher than many folks think and may be more durable than some modern steel in terms of fracturing, especially in extremes of heat and cold.
I am not a metallurgist and don't pretend to be one but there is a lot on the internet in regard to using 12L14 for gun barrels, something it was not designed or intended for.
And Douglas quit making muzzleloader barrels for a reason.