Well, after 7 and a half hours of work today on the 640 pro, I got it all back together! I am at once proud and a bit embarrassed by the whole situation, but I will share the few bits of knowledge I have learned along the way.
1. If you need to replace the sear spring on a MIM hammer, get a couple extras. The first thing I did today was launch another one into oblivion. Third times a charm.
2. The hammer will not drop back into the frame unless two conditions have been met: 1) the trigger is pulled all the way back; 2) the cylinder is attached to the revolver (or the cylinder release is pulled and held back). I foolishly put the hammer in somehow without meeting both conditions, which locked it and everything else in place for about an hour. To remove it, I had to remove the hand. Luckily, these parts are pretty solid, and my poking, prodding, shaking, and prying with a pair of plyers does not seem to have made any lasting marks. For those of you who read the above and shake your heads in dismay, you are absolutely justified. That said, I seem to have escaped mucking up the hammer, the sear, or the hand (mostly).
3. By removing the hand and plopping it back in and installing all the parts, I learned that the hand is controlled by a very important spring officially called the doggerbob, although in some circles it is called the thingermerwhaterjig. Some folks even call it a hand torsion spring. Without it, your revolver is only good for one shot, so you better make it count or make sure the doggerbob is in right. All joking aside, the intricacies of the hand torsion spring would have been lost on me without the following links and photos (actually, even with the links and photos it was lost on me, because I was frustrated... and I had to get my wife to put the trigger back together. I married well.):
4. Of course, to get the doggerbob back into the trigger, I had to remove the bright blue and immensely powerful trigger rest spring thing. Without the proper tools for the task, I had to a flat head screwdriver, a tiny wrench, a fork, and an AC outlet plug for my vacuum cleaner. As it turns out, the AC plug was the most useful for re-installing the reset spring after launching it about 12 times across the room.
5. Although I did not pry the sideplate off, it was a very very tight fit, and it bulged out in a couple places until the sideplate screws were back in. I'm not sure if this means I actually did warp it or what, but its flush with the screws in so thats good enough for now.
6. This should probably be #1. Wear safety glasses!
Well, after paying a premium for overnighting the sear spring screws from brownells (See first post for part #'s) and spending a total of 8 - 12 hours messing things up to require more dissasembly, I am happy to say the 640 has its grips back on and appears to be in good timing. I'll take it to the range in the morning and shoot about 78 rounds of various calibers before I feel comfortable holstering it again. I have learned alot here and I'd like to thank the members of The High Road and encourage those of you as technically inclined as I am to leave the darn sideplate off and just drip some oil in through the frame once the grip is off.
Sincerely,
Triple_T
