I picked up 2 empty casses in Helsinki, Finland last weekend. They pretty much look like big 308 cases. The big one is marked Madsen 20mm, E8, 42, T and a sign, a cirkle with an cross over. Messurments are: Lengt 119mm, with at the bottom is 28mm, lengt of neck 12mm, with of neck 21mm and with of case under neck is about 26mm.

The smaller round is marked at 12 whith a 3, at 3 whith a star, at 6 whith 78 and at 9 whith another star.
Messurments are: Lengt 114mm, with at the bottom is 26,5mm, lengt of neck 14mm, with of neck 16mm and with of case under neck is about 25mm.

Meassurments are aproximatly taken with a ordinary ruler.

Does eny of you know what cases I got?

There is no bullet. i plan to make dummy bullets in the lathe at work, how should they look like?

Most likely is a 20mm Madsen cannon shell, made in occupied Denmark in 1942. Try posting on http://cartridgecollectors.org/.

Here's some information on the 20mm Madsen cannon: http://www.winterwar.com/Weapons/FinAT/FINantitank.htm
http://www.jaegerplatoon.net/AT_GUNS1.htm

Check on Tony Williams pages http://www.quarry.nildram.co.uk/index.htm start with the "data" tables (diameter x length IE 20x119) to get the identity, and than move on to the "photo gallary" to see what it looked like.

RMH
Where about in MI?

Great! Thanks guys.