[fowlplay4]

Gun jamming is a terrible idea, serves only to be a burden on gameplay, and doesn't actually balance guns at all, that's why you don't see it in any popular FPS.

If I was playing CoD or CSS and got a Gun Jammed message, press C J 5 to unjam it, I would press ALT+F4 (F10 in CSS' case) instead.

If they don't want people spam firing, make the accuracy drop while they have the trigger down (I'd imagine they already have this kind of functionality), or lower the rate of fire on the weapon.