How to Use More than Two Weapons in Crysis 2

[QUAKETALLICA]

I played through a good long chunk of the game before I found this out:

If you press the button to customize your weapon right as you pick up a new gun, you'll get the new gun added and won't swap out another primary weapon.

Since this was an unintended bug, you still can't easily switch to different guns by pressing 1 for pistol, 2 for machine gun, 3 for shotgun, etc. The best you can do, as far as I can tell, is to simply scroll up/down to switch guns quickly. However, this is still a great bug and makes the experience far more fun than otherwise being stuck with just 2 primary guns.