I recently purchased a suppressor ready S&W M&P Compact. No matter how finger tight I tried to secure the thread protector, it always started to unscrew after a few rounds. Yes, I could just take it off until my shooting is over, but the pistol seems to shoot more accurately with it in place. Yesterday, while shooting, I had an idea. I took a small piece of masking tape (I use it for pasting bullet holes). I took off the thread protector and wrapped the tiny piece of making tape around the threads. I replaced the thread protector (over the piece of masking tape). It went on with some difficulty, but the thread protector now stays in place. One caution regarding the tape; a little goes a long way.