75mm German Hollow Charge Projectile

[ron3350]

I need help with this German 75mm Hollow Charge Projectile .
It came with a steel case 6391St which has a groove 13mm from the mouth. I thought this was a semi-fixed load?
The projectile is steel with alloy nose and alloy fuze AZ 38. Body stamped : 91 10 43 . Maker could be bnk?
Thin steel driving band but has an odd base extension. Would it be for a tracer? The projectile also has a groove below the drive band.

Length is 235mm with fuze. 215mm without fuze.
I thought the L.I.G.18 projectiles had a flat base. Is this the correct case for this projectile or does it fit other cases?
All information is welcome. What is the correct case for this projectile ?

 

[MINENAZ16]

No doc, but yes German made this round with a base tracer (I saw same example in collections) :





I assume your 6391st case is correct (as your shell is fitted with a crimp groove) :




I saw another case with designation 6341 St without groove :




I don't know if these cases are interchangeable but German made also shells without crimp groove :