1. Join Conflict server. As this is a network desync, it cannot be reproduced in single player or as a listen server host.
2. Join a side.
3. Find/build a mortar pit.
4. Aim the mortar and set it to maximum elevation (as short range as possible).
5. Take one HE mortar round from the interact menu of the ammo box.
6. Inspect the round and change the ring charges to the minimum.
7. Fire the round.
8. Note that the round lands nearby and in a short amount of time.
9. Grab a new round using the interact menu of the ammo box. Notice that it remembers the previous minimum ring charge setting.
10. Fire the round.
11. Note that the round lands far away and takes a long time to hit, if you are even able to hear the round land at all.

Other players on the server will be able to see that your round has 4 rings instead of the previous amount you had.

A workaround is to change the number of ring charges every time before firing a round.