>>10160641The Decepticons finally found the stash of real laser guns.
Alternate handwave: They spent 2 seasons shooting one another with barely-powered guns that hardly had enough juice for a pew-pew, that's why they only seem stunned and inconvenienced from being shot. By the year 2005, they'd been on Earth long enough to no longer be using undercharged weaponry since energon abounds here.
No, I don't like it much either but there you go.