User blog comment:WesTechNerd/Nx Reward/@comment-2183204-20110115224727/@comment-1242640-20110116022234

The default items auto-renew their expiration date after a specific increment of time; it could be a month or until the next Content Update/maintenance. Your USP should fall under same category, but I don't know for sure.

I do know, however, that the Default Upgrades are treated like Permanent weapons, so they will expire eventually (not while you're alive or still playing, maybe)