Rank 1: pistol and 128 ammo
Rank 2: Shotgun and 128 ammo

Going from rank 1 to rank 2 you end up with 128 pistol ammo, 128 shotgun ammo in inventory.

Inventory is not wiped between ranks.

That is the intended behaviour. There is no reason to wipe it between ranks and its much faster to replace 1 weapon then the entire inventory

Ok, sounds good to me. Thanks for explaination.