All XD types are fired with the striker being released from a fully-cocked position. The action of the trigger disengages the striker-block safety, before releasing the sear/striker set. Some argue that this is single-action, as no hammer is involved. The Glocks, M&Ps, Kahr, a few others have that odd half-cocked striker system where the trigger completes the cocking cycle and releases the striker. Not a true double-action. On our 5.25 XD-m I installed a Powder River Precision trigger kit, leaving the trigger spring stock but using all other components with the kit. The striker releases now at 4-4.5#s of pressure, with almost zero takeup and the overtravel controlled by a stop, which PRP molds into the rear of the trigger. No worry of a screw loosening and making the pistol not function. A few snooty competition shooters have tried the trigger, stating it compares favorably to higher-end Kimber or Springfield Armory 1911s. Twelve thumbs up! Jon