If you try to combine M4A1 ammo, 5.56mm, it is capped to 30 shells in your inventory. However if you load them into a 40 shell magazine, then empty out the magazine, it is combined into 40 shells in your inventory.
It appears that the max cap set on combining the shells in your inventory, directly, is set at 30 and should be 40. That or when you unload the 40 shell clip that it should separate into 30 shells and 10 shells respectively.
A) Drag any combination of 5.56mm shells onto another that would make the total number of shells in the space 40 or more.
Expectation: Combined to form a 40 shell inventory slot
Actuality: Unable to combine and the shell inventory slot is capped to 30 shells.
B.1) Load a 40 5.56mm shell magazine with 40 5.56mm shells
B.2) Empty out the magazine
40 shells appear in a single inventory slot
This has been reported previously - make sure to search before opening new issues.
Closing as duplicate of #0003164: Maximum STANAG Ammo stacks depending on the size of the magazine.
Please vote up the original issue to increase visibility, and add any extra information in the notes section.
Thanks