The CUP_lmg_L110A1 (L110A2) and all M249s - CUP_lmg_M249 allow the loading of Apex 5.56mm 200rnd box. But does not show the loaded box unlike all other belts and magazines that are able to be loaded and the reload animation is far shorter than the rest of the belts.
Need to make the reload time the same as the other belts and visually show the loaded box. This is the same without any other mods.
Here is the ammo in question from APEX DLC for the FN Minimi SPW:
All other Boxes:
The Boxes in question: