Sears are inexpensive, hammers are not. With all due respect to Mr. Ford, he's wrong in this particular set of circumstances. The procedure he shows in his video is not the proper way to solve this problem.
The DA camming surface on the bottom of the hammer should never be modified to solve this issue. Removal of material here causes the hammer to fall earlier at the end of the double action cycle, and can cause a host of issues, including problems with incomplete carry up of the cylinder in DA.
New MIM and older double action sears are readily available. Many of the new MIM sears require no fitting at all.
Carter
I realize that we are probably not talking about the OP's problem here, but understand that his gun has MIM parts.
I have read a lot of your posts and I respect you immensely, so understand I am not being critical of you or trying to argue with you. In general, I agree with you, but the old rules have changed when we're talking about the new guns with MIM parts. Parts availability for the new guns isn't the same as with the old pre-MIM guns.
If we were talking about the old case hardened hammers and pinned sear, I would agree with what you are saying, but we're not. Where are you going to find a MIM DA sear for his gun outside of S&W itself? I buy enough parts from Numrich and Midwest that I should probably have my own parking space there by now, and neither of them have one in stock, unless I'm missing something. You can buy the whole hammer assembly but not the DA sear by itself. Brownells and Midway doesn't have them. Jack First doesn't carry any of the new MIM S&W parts. If you know of another source, I'd sure like to know about it.
The MIM parts are drop in parts; they aren't fitted at the factory and aren't designed to be fitted; you get what you get. They can be fitted because they are through-hardened, but they aren't designed to be, so you can't buy oversized MIM factory parts. Therefore any "fitting" here is all luck of the draw that maybe you get one on the upper end of the length tolerance. That's a gamble. The days of buying a replacement oversized DA sear and fitting it on the new MIM guns are gone.
Yes, of course when you remove material off the bottom of the hammer you do cause the hammer to fall earlier in the DA cycle, but there is already variance in hammer fall from gun to gun just based on the normal tolerance stackup inherent with normal dimensional variation between individual hammers, triggers, stud positions and between gun to gun. That happens already between individual samples from the factory. You already have variances in hammer and trigger dimensions from part to part based on the achievable tolerance of the MIM process that exceeds the amount of material removal I'm talking about. You likewise have variances in hammer and trigger stud true positions from frame to frame that affect where and how the hammer and trigger interact with each other. These new MIM parts are not fitted at the factory; they are designed to be drop-in, so sometimes you have stubbers right out of the box. If you can't get another DA sear, what then?
The beauty of the S&W "bypass" hand function vs Colt for example is that its carry-up timing offers a bit of leeway since the sear release happens after the hand has already bypassed the ratchet and cylinder is already locked, if the gun was in proper time to begin with. If you have the proper width hand, typically you get cylinder lock way before the hammer completes full DA arc and fall. The hand has already swept beside the ratchets and is continuing to slide up beside the ratchet before hammer fall. What I'm describing might alter fall a half a degree earlier at most.
For someone who doesn't work on their own guns, the real solution to a stub is to send the gun back to S&W. But if you are a DIY'er, you don't have another option I can see if you can't get another DA sear. I sure would like to know a source that sells them.
