Ratchet: Deadlocked Cheats

After gaining access to the Battledome Challenge "Endzone", use the Holoshield Launcher and/or Mini-Turret Launcher with Shock Mod equipped. After setting up the shields and turrets, equip whatever weapon you want to upgrade, making sure you have the Shock mod equipped. Complete the challenge and repeat until you upgrade your weapons to the desired level. After being able to buy Experience/Jackpot Mods, max out the alphamods on the weapon of your choice to rapidly get to lvl 99 weapons and/or make millions of Bolts.

Go to any Boss Battle and play it. When you start, the game will automatically reload all of your weapon's ammo. Exit the challenge and your ammo on all of your weapons will be reloaded for free. This way you do not have to spend your bolts on ammo.