Once you have a fully leveled up weapon, you are able to evolve it in this section. Evolve is a section where you can increase its star value (Rank), and also to increase a particular stat (e.g. Larger magazines are seen to increase ammo capacity). However, you are required to have one of the same weapon of equal rank. You are also required to have a number of weapons equal to the weapon's rank, and the number depends on the rank of your weapon (e.g. 3 star weapons requires two 3 star weapons)

A 500 evolve 5 star