survival mode weapon upgrades not dropping no matter what difficulty
i have all pistols upgraded to 4, i have some long guns upgraded to 3, some and still just on 1. after defeating a warlord no matter what difficulty or what warlord it doesn't drop upgrades for long guns. i've tried every warlord and none are dropping upgrades at all anymore.
Only Warlord on Stages 6, 8 and 10 drop Long Gun upgrades. If you want level 5 Long Guns you need to play these on Crushing. For level 4 Long Guns on hard and for level 1 - 3 Long Guns on moderate.
Warlords on Stages 2 and 4 only drop Pistol upgrades following the same rules I mentioned above.
I hope I could help! Have fun, mate :)