TL /DR version: Don't crush the threads to keep the screw from moving.
Long Version: My P15 was holding air perfectly since I got it, and after I put the Huma in for months. My power had dipped a little and I was trying to figure out why. I then asked on some forum about that end screw and someone had said to use pliers to crush some of the threads just enough so the screw doesn't work its way out or in, because you can't use threadlocker obviously, air has to get by. I used small needle nosed pliers and barely touched a small section on the middle of the screw. I could barely tell that I had done anything and not wanting to do any more to the screw I put the smallest cable tie I had onto the threads to at least prevent it from working in. I put the gun back together and I was experimenting with different spring set ups for more power. After a couple of different attempts and shot strings, mid-string, all the air dumps out of my barrel. My poppet was no longer holding air. On closer inspection it looked like someone pushed on the seating surface with the blade of a knife. I believe one extremely tiny (microscopic) piece of a crushed thread from that screw must have worked its way through the regulator and pass the poppet creating that scratch. It is the only thing that had changed and the only thing that makes any sense. I managed to fix the poppet, which was a real pain without a lathe, and the gun works fine now. Leave the threads alone. That's my cautionary tale for what it's worth.
Mod Edit: Moved to Other Parts, Accessories and Equipment forum
Long Version: My P15 was holding air perfectly since I got it, and after I put the Huma in for months. My power had dipped a little and I was trying to figure out why. I then asked on some forum about that end screw and someone had said to use pliers to crush some of the threads just enough so the screw doesn't work its way out or in, because you can't use threadlocker obviously, air has to get by. I used small needle nosed pliers and barely touched a small section on the middle of the screw. I could barely tell that I had done anything and not wanting to do any more to the screw I put the smallest cable tie I had onto the threads to at least prevent it from working in. I put the gun back together and I was experimenting with different spring set ups for more power. After a couple of different attempts and shot strings, mid-string, all the air dumps out of my barrel. My poppet was no longer holding air. On closer inspection it looked like someone pushed on the seating surface with the blade of a knife. I believe one extremely tiny (microscopic) piece of a crushed thread from that screw must have worked its way through the regulator and pass the poppet creating that scratch. It is the only thing that had changed and the only thing that makes any sense. I managed to fix the poppet, which was a real pain without a lathe, and the gun works fine now. Leave the threads alone. That's my cautionary tale for what it's worth.
Mod Edit: Moved to Other Parts, Accessories and Equipment forum
