If you want o get far in Contra: Rogue Corps you’re going to need to upgrade your weapons.
There are many benefits to upgrading your weapons in Contra: Rogue Corps. The main benefit is that it increases their base stats, meaning that when you level them up they grow even stronger than before. Upgrading a weapon also increases the number of B.A.D. equipment points it has available, enabling you to equip better or more mods.
To upgrade weapons in Contra: Rogue Corps, you first need to get them to level five. That means completing missions with them. When they’re level five or more, go to the Workshop in the Base Camp and select the development option. On the next screen, press the right shoulder button to move over to the upgrade tab, and then select the weapon you want to upgrade.
Both money and materials are required to upgrade weapons. At the bottom of the weapon upgrade screen you’ll see that you need to sacrifice B.A.D. mods adding up to certain amount of points, and possibly yet more B.A.D. mods from a certain category. Try to select the B.A.D. mods that are the least useful to you. If you need more money, consider selling useless body parts. When you’ve fulfilled the B.A.D. mod conditions and have enough money, hit the execute button. Your weapon will be upgraded, and you might be granted one or more bonus levels to make it even more powerful.
It’s costly, but upgrading your favourite weapons is very much worthwhile in Contra: Rogue Corps.