I purchased and installed the DPM recoil spring for the Hellcat. I've only shot 50 rounds so far. I want to shoot at least 200 rounds before switching back and forth between the OEM spring and the DPM before giving a review. Waiting for ammo prices to go down more.
I also changed the Gen 1 trigger to the Monarch trigger. Installed the M*Carbo trigger spring kit and the stainless steel striker sleeve (liked it better then the Lakeline one which I also had purchased but it is still a good product). Installed the True Precision DLC barrel (non-threaded).
I still want to fine tune the trigger so I will take it apart again to adjust the break and reset. Otherwise, trigger still feels better then the Gen 1 trigger after shooting 50 rounds.
I also installed the Lightning Strike Steel strike firing pin from NDZ (will not fit in the Lakeline steel striker sleeve).
Hopefully in a couple months I can give you all a review of the DPM recoil spring system.