How to Unlock Infinite ATM-4 Rocket Launcher
Beat Leon’s story on Hardcore with S+ Rank (doesn’t matter if A or B scenario, either will unlock it). The time requirement is 2:30:00 for A-Scenario / 2:00:00 for B-Scenario. To get S+ you are not allowed to use any infinite ammo guns. You CAN use the infinite knife. If you use infinite ammo guns, the game will restrict you to S rank. Furthermore, you can only make up to 3 manual saves for S+. If you make 4 manual saves it turns into S rank.