After reading on this forum about checking the main spring screw on the revolvers....I took the grips off my two new guns. The 500 and the 686 both had exactly the same amount of turns to go until tight. also I noticed the threads had loctite on them. So my question is...is that an adjustment I just wiped out? Is the tension on that spring that critical that the factory would measure it and stop tightening at a certain point? Now they are both in all the way and it didnt seem to make any difference on dry fire for single or double action trigger pull. What say you experts?

I don't trust locktite to keep the strain screw secure so I always run them fully tightened. If I want to reduce the mainspring tenstion to a specific level I've made up shims that fit under the head of the strain screw so that I can tighten it down fully while positioning it for a bit less mainspring tension. While it's not very difficult to make these shims it is a bit fussy. What you do is start by drilling some shim stock with a 0.147 diameter drill. Then you clip it out and shape the outer diameter to 0.218 inch centered on the .147 diameter hole. Another alternative is to purchase some spare strain screws and shorten them in alternating steps until you start to see misfires, then install a strain screw about 0.005 inch longer than the one that caused misfires. BTW, it doesn't take much to have a large effect on the DA trigger pull. I have 0.030 inch of shim under the strain screw on my 625 and it reduced the DA trigger pull from 12 lbs to 8 lbs.

So, what you are saying is......I probably did wipe out a "factory" adjustment for a certain (whatever factory specs is) trigger pull?

I will have to do some more dry firing and see if its really different......If I can live with the trigger pull as is, I assume theres nothing bad about having it all the way tight even though S&W didnt have it all the way tight???

Chris,

Those screws need to always be tightend completely. There are better ways to change/improve trigger pull.

Mike

Yes the screw needs to be in tight for defensive weapons. I was taught in armory class you could back them out 1 and 1/2 turns and then tighten 1/8 turn until weapon fired dependable. That was 30 years ago for PPC competition. Today Wolfe and others sell springs that are reliable and you can still keep the screw tight. I have never depended on loctite for dependability on a defensive weapon.

Smith did have it "all the way tight", it just probably loosened and backed out due to vibration from firing. It's common.
You did NOT "wipe out a factory adjustment".
Listen to what others are telling you here. The strain screw was NEVER meant to be an adjustment.

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Dick

OK, cool.........I just did a bunch more dry fires and the single action is as light as before (I cant tell a diff) and double action is still smooth, and stages easier at cylinder lock now.....so thats a bonus. Gonna leave it tight

I have never seen a S&W that was new out of the factory that had Loctite on the strain screw. But maybe they do now. I would recommend leaving it tight and checking it occasionally. They can back themselves out over time.