In message , "Keith Willshaw" wrote:

You are comparing Apples and Oranges

The napoleon was a smoothbore and its production involved
much less boring and turning than a rifle

The true comparison is between an iron
smoothbore and a napoleon.

Wrought Iron or cast iron? The 3-inch Ordnance Rifle was far more expensive
than the cast iron Parrot. The Columbiads though were coastal/siege artillery,
and also not comparable to a field gun. A better comparison would be between
the iron guns and the bronze James Rifles (pattern II?) (though I'm not certain
if the latter were wrought or cast bronze). Unfortunately, info on the James
(the manufactured as rifles version and not the old rifled 6 pounder
smoothbores) is rather rare.

--
Regards,

Michael P. Reed