Call of Duty: Modern Warfare 3 Zombies players can spend entire matches upgrading their guns with the Pack-a-Punch machine, only to lose them when the game is over. However, there is a method to keep all your upgrades to use in the next game.
How to Keep Pack-A-Punch Weapons in MW3 Zombies
Players can technically keep their Pack-a-Punch upgraded weapons by visiting the Seatown castle and interacting with a grave on the rooftop. This grave will strip your weapons of all upgrades and place them in your inventory to use in future matches.
The Seatown castle can be found on the west side of the red threat zone, and the rooftop is easily accessible from either the water via rope or stairs on the mainland. There will a small gravesite on the rooftop of the castle and players can interact with it, or “Pay Respects,” which will cause a reward portal to open up.
The grave will remove all upgrades made to your weapon, and place them in the reward portal. This includes any Ammo Mods, Aetherium Crystals, and Aether Tools.
Players will need to have sufficient room in their rucksack to keep all of their upgrade tools. It is also important to do this at the end of the game, as you will be left with your base weapons and will still have to exfil successfully to keep all your upgrade tools.
So, you technically do not get to keep your Pack-a-Punch weapons as is, but you get all your materials that were invested in it. Keep these tools in your rucksack for the next match, and then apply them to your weapon to essentially pick up where you had left off in the last game.
For more on Modern Warfare 3 Zombies secrets, check out our guide on how to open the locked vault and the chessboard solution.