Having played GURPS for well over a decade now... I hate crunchy! I would only go with stresses and such for a weapon under 2 circumstances:
1) The weapon is used in a non-standard way. Such as using your AK-47 to parry an axe swing from a big guy.
2) It otherwise would make sense. A catch all reason for odd things.
I would not track this sort of thing for every weapon all the time. An alternative is to just skip the stress tracking for the weapon and go right to consequences for the weapon in the same manner one works out a concession.
Well, if you don't like crunchy, don't use "
Fuego" for prolonged periods of time, a quick blast should just leave 'em crispy. And "
Arctis" is right out as well.
Seriously though, for in-game play I would generally handle such a situation by taking into account what is occurring. If the player is using a gun to parry a Weapons attack from another character, or a Fists attack from a character with Inhuman Strength or better, that I'd put an Aspect on the gun, something like "I'm a gun, not a billy club!" which would last until the character has a chance to have someone check/fix the gun. In the mean time, I would have 'fun' with the Aspect, and the player would have the chance to get Fate points, and/or spend them to keep using the gun anyway. In short, I would basically just skip a weapon stress track altogether if what happens could damage the weapon.
-Cheers