and before you ask.....YES I used the "enhanced" firing pin from RED X arms http://www.redxarms.com/product-p/5061.htm this is the upper https://www.bearcreekarsenal.com/bc...2x39-carbine-length-gas-system-w-15-mlok-rail I put the firing pin in. Went to the range with wolf ammo. Pulled trigger. Nothing but a tiny click. Ejected that round, tried again...same thing. Eventually I put the regular firing pin from my working upper in and finally it fired maybe 5 times out of about 20 attempts The only thing I can think of is that I have a RAVE140 trigger and maybe the hammer spring isnt heavy enough. (I have sent an email to Rise Armaments asking about it) I dont remember the exact method used to get it to fire. for instance was the magazine in or out? Dont remember btw using ASC mags any ideas??