What is the difference between those 2 20mm

Both cases have 110mm the green projectile HS=TR 1944 20mm MK||
long neck
The other the same 110mm case but black projectile HS=DA ^C 45 20mm
short neck

The top one is 20x110 Hispano, used in planes mostly.

The bottom one is 20x110 Oerlikon, more used in Anti aircraft tasks.

Not trying to pick on your wording, but the way you state it, it seems that you might be saying “…the same 110mm case…” but you mean the same case LENGTH of 110mm, but certainly NOT the same case, as one is a rebated rim and one is rimless. You could add the 20 X 110 USN case and have the complete set of same LENGTH case types…

1 Like

Taber 10
you told me what i wanted to know,ok we do it your way same LENGTH case type
What got me the most was the difference in neck shape and the rebated rim
difference,Thanks again