MegaCaliber3 (M3) Cannon Robot

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The MegaCaliber 3 Cannon Robot is good if you need to blow up buildings or heavily armored vehicles without needing to move heavy artillery around quickly. This is good in urban fighting or surprise attacks. It’s basically walking artillery. And since it is a robot, it also means that you don’t need people to move it around which keeps soldiers farther away from the danger. The explosives are very powerful. The problem is that it only holds 10-15 shots before it is out. After that it is mostly useless. It’s best where the fighting will/may be quick.
There are attachments which add more shots but that means if the droid is hit correctly there is a much bigger explosion from the volatile explosives.