This is Too Good
After you finish beating Reactor in Dread challenges there is a challenge called Endzone. Put Exterminator difficultly on and use the weapon you want to upgrade .
Doing this you will also get lots of bolts if you use bolt mod I think that is what it is called. Exterminator difficultly is only when you beat this game.
More tricks, tips and cheats for this game are right here - Ratchet: Deadlocked cheats
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