Would anyone know the best cartridge to start with making a 2-bore on? I know the Ed Hubel is using the 20mm brass to mmake his 4-bore off,so i was wondering what would be the best to start with for a 2-bore. Also where can i find 200mm
navy?I understand this would be largest of the 20mm family.

Perhaps I shouldn't say this, but Ed was eyeing my 37x169R case as a basis for a 1 bore cartridge. Perhaps somthing in a 25 or 30mm Rimmed would do what you want?

If you haven't done so already, you should look over the specs on Tony Williams (hope I spelled that right) site. Find one of his posts on either the Military surplus or cartridge collector forums.

Edit, found it for ya.

Tony Williams Military gun and ammunition website:

http://www.quarry.nildram.co.uk

Discussion forum at:

http://forums.delphiforums.com/autogun/messages/

This fall I will have some steel 25mm cases and will
setup a 2 bore cartridge.These cost 12-15 bucks each.Can't
find any brass ones reasonable and they are scarce it seems.
Ifanyone knows where brass 25 mm cases can be had
reasonable and in abundance let me know, asap.The steel
case is quite strong and once set up should hold 2 bore
regular pressures and reload without resizing. Steel isn't the best for resizing.If I can find the Jap 37 mm ones that tailgunner mentioned we will also make a one bore.And it is
already rimmed.Ed.