the tool is injecting the memory change, as long as the memory/game allows infinite then its possible, for example revelations the code i was working on at the time set your ammo to 999/∞.
the 999 decreases but because your reload is set to ∞ it wont decrease, i did however find an address that froze the ammo completely but if you died or had to restart the game would crash when loading the level again.
when i come back to this game (it would help if i had a 100% save so i can easily access all levels) i will try to do a code where the ammo just shows as ∞ (like the rocket launcher does)
And with Mercenaries i found the address for the timer, then looked a little beyond this and found the address and set a value so it froze the timer.