I recently installed an Apex Tactical polymer forward set sear and trigger kit on my M&P9. This included new trigger, trigger return spring, sear, sear spring, striker block, and striker block string . When I took it to the range yesterday, I had two failures to fire and had light firing pin marks on the primer. I didn't try any more rounds, but retried the same ones and no luck. I didn't tune the trigger bar loop to add overtravel, because I don't mind not having any. Any ideas? Should I tune the trigger bar loop?