Do weapon mods last one match?
Solution 1:
Weapon mods are a permanent item. Some only work with certain weapons/types of weapons, which may make it seem like they disappeared, but they cannot be expended by any means and are yours unless you decide to delete/get rid of them. Hope this helps!
Solution 2:
No, there are not! Once you get them, you'll keep them forever, even if you reset your character.
(you can even share it between your differents characters)