Trying out a new scope this morning. No matter what I was trying, I could not shoot a tight pattern. Out of five rounds, three would hit a four inch circle, the other two were scattered all over.
Got home, brought out the Shoo-Wrench, found the barrel nut was so loose I could spin the wrench with my fingers. The nut wasn't tight at all.
Tightened it back down, will have to wait for the next range trip before I can see how my accuracy improves.
IMO, the barrel nut loosening is a fundamental design problem that needs to be addressed by S&W.
The next time I take it all apart, I will use a drop ofe locktite or similar to hold the nut in place. Not a lot, just a drop