help on 3rd generation auto

[Arkieron]

I have a 3913 that is off my 12 lb scale on DA trigger pull. I ordered a wolff hammer spring and a trigger plunger spring to try to get this down to a reasonable manner. The reduced power hammer sping didn't help a bit. I have the frame mostly stripped in an effort to polish the drawbar and hammer/sear surfaces, and really clean things up. The only instructions I can find on line is S&W's instructions on the Model 59. There are enough differences to cause me problems. The Schematic in my owners book is not a 3913, but a 1006.

The Beretta guys have a wonderful series of videos that demonstrate a detail on a Model 92. Using that reference and some hammer/sear charts, I was able to help that trigger a bunch. I would be joyful to replicate anything close to that 8 lb da and 4 lb sa pulls.

Two questions. What is most likely the major contibutor to my bad trigger on the 3913? Second, does anyone know a good source material on assembly. Any help would be appreciated. Ron

 

[SW CQB 45]

I have found that the MIM trigger components have much smoother trigger pulls out of the box compared to the older flash chromed.

since these guns were just part of a assembly line, they were just put together after functioning and there was no refinement.

I would caution changing angles on hammer hooks or sear surfaces. if your piece is MIM components, the actual hardness is only on the surface and if the hardness is removed by stoning, the wear is accelarated.

I can only suggest to lightly smooth or polish.

you say no positive results with the mainspring. did you change the trigger rebound to?

if the pull goes too light from lighter springs, you may experience misfires from light hammer strikes.

most spring replacements require both to go lighter.

if its lighter and you get misfires, then I suggest you go back to factory setup if this is a CCW.

AGI video is a good ref for re assembly and disassembly.

good luck

 

[HEADKNOCKER]

Here's a few videos that I found on youtube that show the 3rd gen S&W, Quality isn't that great but does show the frames parts being put back in in video #2..

YouTube - Smith & Wesson Mod 4506 advanced takedown

YouTube - Smith & Wesson Mod 4506 advanced takedown Part 2

YouTube - Smith & Wesson Mod 4506 advanced takedown Part 3