Congrats on a good cleaning reportedly resolving your problem. Yeah, bad enough fouling can create a Skips-DA condition. Especially if the nasty fouling involves the disconnector and its area in the frame.
Depending on the age of the gun, and the age of the armorer manuals, none can find
No Pick Up Double Action &
Skips Double Action sections in the Trouble Shooting sections. In the older manual the No Pick Up DA listed probable causes as being a defective hammer and/or drawbar, or a disconnector. Then, the Skips-DA section listed a too long disconnector (long tail disconnector); defective drawbar; short drawback spring (drawbar spring); worn hammer notches (pickup or throw notches); or a newly replaced drawbar having too much material in the drawbar head's radius. The newer manuals just listed either a broken drawbar or a dirty gun.
The disconnector tail dimension issues were said to have gone away when the nylon disconnectors replaced the old steel ones. I once met a newer armorer instructor who had never even heard of the possibility of an older long tail disconnector condition. I had to show him a manual from the 90's where it was listed.
FWIW, as John mentioned, improper reassembly of the drawbar plunger and its spring can cause a loss of tension in the drawbar tail being sufficiently lifted upward so the drawbar notches will properly engage with the hammer's DA notches (either Pickup or Throw notches). This can happen if the drawbar plunger head isn't properly located in the recess at the front of the drawbar head. It's not difficult to become distracted while installing the drawbar over the trigger prongs, and miss seeing the plunger head drop out of the drawbar head's recessed notch. This is why one of the tests is checking for sufficient spring tension of the drawbar tail during that part of frame reassembly. Also, a broken drawbar plunger spring might be involved. Or, if someone has installed a lighter drawbar plunger spring, it might not sufficiently power the drawbar tail at times.
Worn hammer and/or drawbar DA notches? Broken drawbar (at the rear, either in a corner or the middle, at the disconnector tab)? Self explanatory.
The extra material behind the drawbar head, in the radius cut, isn't something you see happen much. I've only seen it happen once, and that was out of more than 1000 pistols of both early 3rd gen, and late production 3rd gen guns. It's so infrequent that they didn't have armorer students even practice filing the drawbar radius during the armorer class. They just briefly talked about it. (We spent a LOT of time filing sear release levers and extractors, though.
)
It's usually something that may happen when a new drawbar is installed, oddly enough, but the time I had it happen was in a fairly new 3913. It requires carefully removing material in the radius cut, using a 5/32" round file, so the drawbar tail is able to reach back far enough so the drawbar notches can properly engage the hammer's DA notches. However, if
too much material is removed, then the drawbar's forward movement may not go far enough forward to release the hammer to fall in DA before the trigger bottoms out back against the frame (inside the trigger guard). Then you start over with a new drawbar.
Just some thoughts.
