APFSDS:

It has 3 components on the projectile.
-The fin part
-The main penetrator body
-The sabot

The fin part is for aerodynamic stabilization of the penetrator body. Because when the length of the penetrator is 20 times larger than the diameter, it wont travel straight and smooth in the air. so ...

Hello.

I have been researching on KE weapons. The only info i couldn't find is case diameter. If you have information, can you please tell me the case diameter of 120 mm APFSDS ? (please look at the picture that i attached. I draw what i want)

Thank you.