Little bit of background, I have many 1911's and have never had this situation before. On one of my Dan Wessons, a Valor, I had been getting an occasional hammer drop to the to the mid notch when dropping the slide on a magazine with shells in it. I had stoned the sear before, and set the trigger pull to 3lb10 oz. While this always bothered me, I really didn't shoot this much so put if off for awhile. I had a little free time yesterday and decided to put a little more tension on the sear to try and correct it, but knew it probably wasn't really the issue. Once I got it up to about 5lbs it held, but at that point figured the problem was really the sear, and that I probably had taken a little too much off this one, and decided to replace it with a spare one I had laying around. Did a very minor stoning on the spare, put it in, tweaked the spring a bit and ended up at 3.9lb. Everything seemed fine, no sign of hammer drop. Cycled the pistol a bunch of times and all seemed good so I went out back to shoot a few rounds with it. Right away had issues with it working for a shot then not firing with a two hand hold. Wiggled the thumb safety a bit and it seemed to be rising about a 1/32"- 1/16". Would work after pressing down again. Keep in mind this is the first time this has happened to me with 1911's in the over 20 years I have been shooting them. Tried a one hand hold, all was fine. Took out a few other of my 1911's to compare the feel of the thumb safety when down and while most of my other ones seemed to click in a little more solid in the down position, although a couple others felt similar to my Wesson Valor in that even though there was tension on the thumb safety in the fire position, you could wiggle it up and down that 1/16" or so with less effort than some of the others. So I guess what I am asking is does anyone have any Ideas? I looked up a couple of youtubes, and it seems to be a simple procedure to work on the thumb safety to make it work, but am wondering if anyone has any idea on how to firm up the click on it first before I go and remove material from the thumb safety if it is not really needed. I did shoot it some more and it seems to be working, so obviously seems to be working on the ragged edge, but would like to make it right.