[Cant Max Mods]

Currently its just one mod wondering if there are any others like this but for some reason when i try to max Ammo Drum it says it already is but im stuck at 25%

[Unable To Install Ammo Drum On Paris + Bonus Glitch]

for some reason i am unable to max out ammo drum. every time i try it says that it will exceed capacity so im stuck at 25%