Keith Willshaw wrote:



The cost of boring
(drill the main center tube) and turnign (trunnions) is the same.

However the machinery required to cut rifling in a cannon
bore is of an entirely different order from the simple boring
process adopted for a smoothbore.

no it is not. you still advance the cutterbut you synchronize the
forward and rotational action. its called a "screw cutting"

There's a good reason
why rifled cannon didnt appear on the battlefield before
the 1850's and the rise of the machine tool is a large part of it.
It wasnt until 1841 that the first standardised screw threads
were introduced by Whitworth for example.

Does not affect cannon. all you need for cannon is a precisly cut tool
feeding controller. Cannon barrels did not require the precision that a
machine screw required.

Moreover the Parrott's were reinforced with wrought
iron hoops on the breech.


Sure, but they did burst. a lot, because the thermal effects werenot
well understood.



It being softer thats hardly surprising.

but you could also make guns lighter than an equivalent Iron gun. which
is why iron was preferred for naval and caost defense gusn and bronze
for field guns.

Vince