I was probably a little limp-wristed with the tightening. I was afraid to strip it.
I did just that last night and cranked down on the sucker. While I didnt fire it, I racked the slide and let it slam forward about 50 times with NO loosening. I know that isnt as good as running ammo through it but it was the best I could do without shooting at my garage door. hahaha
I guess I will try next time.