I had just the opposite problem when I got mine right after they became available. With reasonable torqueing I had the screw come loose twice. Also the barrel screw once. I used blue thread locker on them both and have had no further problems.

This is a fine gun and shoots almost as well as my 41 at a much lower price. I currently have a second one on order with a threaded barrel so silence will be golden.

A heat gun from Harbor Freight is a better option for removing thread locker from places where it shouldn't be. Don't ask me how I know this.

Also factory service from S&W has been to my satisfaction both for warranty work and repair on older guns. Good luck.