Can you upgrade a gun in derise nazie zombies twice?

yes this is actually very easy though has an additional price of 1,000. what you do is when you have your third weapon you take out your bouncy bettys (don't set them) after you have upraded it. you then get your weapon with the bouncy bettys out giving you a upgraded third weapon

if you did not know to get a third weapon go to the pack a punch machine and insert your weapon then head over to the kar and get it for your old weapon(you should only have 1) now go grab your other weapon and wow you have 3 weapons (this is the easiest way............)

theres another involving the random box and dyeing though i have never been successful with this one. i havent tried the other one though that's how my friend told mme to do it :) =) XD :p (faces lol)