Recently trigger pull effort on this rifle suddenly became near zero. Nice for targets, but probably not good for hunting. This is my deer rifle.
I found the attached article. When I checked out the trigger, I noted that the sear engagement screw could not be turned clockwise one detent. Of course I wanted to back it out to increase sear engagement. I backed it out about 1/2 a turn, which has increaced the effort required to fire.
I have never experienced a trigger adjustment screw changing. In fact, on many factory triggers, the screw is painted to prevent spontaneous movement (and, also, perhaps, to indicate if someone has adjusted it!). It sounds like you have solved your too light trigger pull. However, I'd suggest that you degrease the screw and coat it with nail polish.
I wonder why the screw backed out?
JimF -- a pilgrim still <*}}}><
"Preserve Game -- Use a Trained Dog"
Like GLS, think something odd has happened. Own a tang safety Ruger myself. One that I had bought used. Trigger on it was too heavy to my liking.....5 lbs plus. Tried adjusting it down myself, turning what I assume was same screw as you turned and it didn't seem to reduce my trigger pull as much as I'd hoped. Ended up putting a Rifle Basix trigger sear in the rifle, which got me down to a trigger pull I wanted.
Like GLS suggested, rifle needs to be checked by someone (gunsmith) familiar with a tang safety rifle.