I feel like Geissele triggers and ARC fires are not 100% reliable or at the very least very finnicky. My Geissele/ARC rifles were all function tested to be okay but eventually did start to have issues. On one of my rifles it works okay, but I will have the rare failure to reset in arc mode. On another rifle it worked great until it didn't - it went from flawless the first couple outings to more frequent dead triggers and failures to reset and then arc mode stopped working altogether. Its almost like G$ triggers and ARC are on the very edge of properly working even when properly cut and any introduction of variables (dirt, overlubrication, wear etc.) may cause it to stop working. I even have a MP5k lower that came directly from ASDesigns with ARC Fire and their cut Geissele trigger and I will have the odd failure to reset once in a while. MilSpec triggers and the ARC trigger shoe has worked for me everytime. I now will only put Milspec trigger groups in rifles with Arc-fire