Bofors 40mm QUESTION Air Cooled vs. Water Cooled barrel

[daninnm]

I have an M3 40mm Bofors gun manufactured in 1942 for which I want to obtain a new barrel. I have been offered several but each of those seems to be the WATER COOLED barrelw ith the jacket removed and the spring removed. I have the spring on the present (but cut) air cooled barrel.......QUESTIONS ARE:
(1) will the water coolled barrel without the jacket fit in place of the air cooled barrel WITHOUT MODIFICATION
(2) if not, what mods can be made (if any) to make it fit and actually fucntion?
(3) any difference in the barrel to breech ring threading?

Dan in NM
505-269-2056

[Stellan Bojerud (RIP)]

The US Army 40 mm Bofors and US Navy (watercooled) are made to different specifications and the parts are not interchangable.

The Army guns were a copy of the British Mk I obtained from GB. The Navy guns were made to Bofors specifikations plus one gun bought from Sweden.