In resident evil 5 can you play mercenaries mode with your upgraded pistol and unlimited ammo?

In Resident Evil 5, you can play Mercenaries mode with your upgraded pistol and unlimited ammo, but only if you have previously unlocked those features in the main game. Unlimited ammo is available for weapons once you've completed the game and obtained the necessary upgrades. However, keep in mind that the specific rules and available weapons may vary based on the version of the game you're playing.