If I remember correctly, theres a really weird coil type spring under one of the grip panels. I dont even remember if it was a trigger spring or what. Or if it was even on all the 3rd gen or just specific models. Anyway, the spring is terrible and seems to always break. The only replacement for it is a new factory one of the same design. Honestly thats been a few years back and that was the only time I have even been in one of those guns and Im sure someone on here knows way more about them than I do.