Call of Duty Black Ops 2 Zombies survival tips?

[PWiz]

Hey guys, I'd really appreciate if anyone out there can give me tips for training Zombies in Survival in the Town map, because I keep getting stuck near round 30 or so when I have to Pack-a-Punch in the middle of the round since my ammo keeps running out mid round and I have to use the Mystery Box over and over: no gun lasts for more than a few minutes unless its upgraded.

 

[Borg]

It doesn't look like people here have any advice. Have you tried posting your question to a Call of Duty forum?

 

[PWiz]

Hahaha not yet but I've tried it on Google+