Just curious as to what primers you are using, definitely try the primer over the strain screw especially if the new mail spring doesn't work any better, Larry
S&W 625 not firing reliably on double action
- Thread starter Korum
- Start date
SuperMan
Member
Guess bottom line for me would be if I bought a S&W .45 ACP revolver brand new and it had a headspace shelf that was "supposed" to be there for headspaceing the rounds and didn't, that is a factory defect which they would be replacing.
If S&W could make them right in 1917 they should be able to do so now...
Bob
If S&W could make them right in 1917 they should be able to do so now...
Bob
SuperMan
Member
Korum...just wondering...what exact model of 625 do you have? New one, JM, PC, older 1989... Just wondering when this gun was made...
Thanks...Bob
Thanks...Bob
When S&W first offered the 625 it was a period when Steve Melvin and the British were taking over and pushing CNC machines into production. There were quite a few problems with these guns in the beginning and the questions of moon clips or not was a hot topic. Not to mention finding uniform and correct moon clip thickness.
Auto rims took care of this
So first off I would be very surprised to find a bad SS main spring
Measure the mainspring weight recommend 45-52 oz. Adjust
Remember SA hits harder moves farther than DA
Measure headspace. Wedge cylinder back .093" to .098"
Finally if this is an early 625 with Pachmayr grips it's possible the grip screw is hitting the mainspring. This wasn't discovered until long after the first run was released by gunsmith Ron Power. It was hushed up by the factory but they very quickly changed grips. The screw was making contact with the mainspring as it arched into full hammer profile.
Rick
Auto rims took care of this
So first off I would be very surprised to find a bad SS main spring
Measure the mainspring weight recommend 45-52 oz. Adjust
Remember SA hits harder moves farther than DA
Measure headspace. Wedge cylinder back .093" to .098"
Finally if this is an early 625 with Pachmayr grips it's possible the grip screw is hitting the mainspring. This wasn't discovered until long after the first run was released by gunsmith Ron Power. It was hushed up by the factory but they very quickly changed grips. The screw was making contact with the mainspring as it arched into full hammer profile.
Rick
lefty_jake
Member
- Joined
- Jul 18, 2015
- Messages
- 228
- Reaction score
- 247
When a revolver misfires in double action, my first thought is "What is the double action pull weight?" What I really want to know is "how much tension is there on the mainspring?" And as garbler said, the best way to judge the mainspring tension is to measure the weight needed to move the hammer. But even though the rebound spring, and internal friction, can affect the double action pull weight, that weight still gives a good approximation of mainspring tension. So if the pull is less than 8 pounds, then a longer strain screw or a shim is probably the answer. And if the pull is over 11 pounds, then there is some other problem, and I know I would not want to make the pull heavier. If the pull is between 8 and 11 pounds, then knowing exactly where it is still gives hints about how to proceed.
And for anyone working on these problems who has no way to measure pull weight, I would say "stop." Either get a trigger pull gauge, or makeshift one with a bucket and some weights, or seek assistance. You can't get good results without some way to take measurements and assess the results. This is just one small aspect of having the proper tools to allow yourself a chance at success.
Wolff Mainspring
I just got my Wolff Mainspring and installed it in my 625. I had a bit of trouble getting the sideplate back in place but it finally went together and the pistol worked fine so I apparently got everything back together okay. I'll load up some more full moon clips and go to the range probably tomorrow. Here's a pic of my 625-8 with a 4" barrel.
I just got my Wolff Mainspring and installed it in my 625. I had a bit of trouble getting the sideplate back in place but it finally went together and the pistol worked fine so I apparently got everything back together okay. I'll load up some more full moon clips and go to the range probably tomorrow. Here's a pic of my 625-8 with a 4" barrel.
Last edited:
Wolff Mainspring Failure
The Wolff Mainspring was a joke! It wouldn't fire either double action or single action! Finally after I tried several revolutions only one round would go off! I thought a Wolff spring would be stouter then the stock spring! Which way do I bend the mainspring to increase my hammer pressure?
The Wolff Mainspring was a joke! It wouldn't fire either double action or single action! Finally after I tried several revolutions only one round would go off! I thought a Wolff spring would be stouter then the stock spring! Which way do I bend the mainspring to increase my hammer pressure?
Last edited:
If you install a Wolff power rib spring in a round butt gun you will need to use a 1/2" set screw to get enough tension on the mainspring. The combination of the rib in the spring and the change in geometry of the round butt causes this. I use a wheeler trigger pull scale and set the D/A pull at 8 pounds. Occasionally I will have to increase it to 8 1/2 pounds to get reliable ignition. It's a very quick and easy process at the range.
scrufff
Member
Try putting a piece of tin(shim) in between the strain screw and the spring. Strain screw might not be long enough to apply enough pressure
andyo5
Member
Many owners try to lighten the trigger pull by shortening the strain screw, or by unscrewing it a couple of turns. The former is legitimate so long as you don't go too far. The latter is not. A good 'lightened' trigger will yield an 8 pound DA pull and a 2 1/2 to 3 pound SA pull. But lightening the trigger pull can cause failure to ignite the primer. It is the DA pull which will suffer first.
The good news is that if you have a frame mounted firing pin, you can replace it with an extended length firing pin that will restore your reliable ignition. Apex makes a version (which I use), and there is at least one other company that does so as well. Replacement of the firing pin is pretty simple. Instructions are included.
The good news is that if you have a frame mounted firing pin, you can replace it with an extended length firing pin that will restore your reliable ignition. Apex makes a version (which I use), and there is at least one other company that does so as well. Replacement of the firing pin is pretty simple. Instructions are included.
Wolff Mainspring removed
I pulled the Wolff mainspring and I'm replacing the original spring. It's a lot stiffer then the Wolff. However I'm having trouble inserting the spent primer the other posters recommended to increase my hammer drop weight.
I pulled the Wolff mainspring and I'm replacing the original spring. It's a lot stiffer then the Wolff. However I'm having trouble inserting the spent primer the other posters recommended to increase my hammer drop weight.
On the round butt guns the spent primer is a tight fit until the mainspring is tensioned a bit. I used a piece of wood to wedge the spring back a bit to get the primer inserted.
slickracer
Member
There's nothing wrong with Wolff springs , if setup properly.
Problem solved!
I reinstalled the factory mainspring. I tried using both a large pistol primer and a small pistol primer. Both fit inside the strain screw. Both had the anvils removed. I couldn't flex the mainspring far enough to get the primer cup between the spring and the front of the grip frame and finally gave up on this attempt. I cut a flat shim out of .018" sheet metal and placed it in between the strain screw and the mainspring. After reassembling the pistol I dry fired it both single action and double action. The pistol seemed to have a stiffer hammerfall. I took it outside and testfired it double action 5 rounds and all rounds went off the first time! Problem solved! Thanks for everyone's input!
I reinstalled the factory mainspring. I tried using both a large pistol primer and a small pistol primer. Both fit inside the strain screw. Both had the anvils removed. I couldn't flex the mainspring far enough to get the primer cup between the spring and the front of the grip frame and finally gave up on this attempt. I cut a flat shim out of .018" sheet metal and placed it in between the strain screw and the mainspring. After reassembling the pistol I dry fired it both single action and double action. The pistol seemed to have a stiffer hammerfall. I took it outside and testfired it double action 5 rounds and all rounds went off the first time! Problem solved! Thanks for everyone's input!
Last edited:
4barrel
Member
What post #4 said -large primer-but I never removed the anvil. You have to back off on the screw to install. <screw to anvil side> It worked for me several times. Don't try to bend the spring. Glad it is fixed.
Last edited:
308 Scout
Member
Guys, if the mainspring were the problem, then wouldn't it misfire SA and DA??
I'm wondering if the problem is with a with one of the surfaces, either on the trigger or hammer, that determines how far back the hammer is drawn in DA mode. In other words, could something be worn such the hammer is not rotating back as far as it should thereby not getting the full benefit of the mainspring?
308S
I'm wondering if the problem is with a with one of the surfaces, either on the trigger or hammer, that determines how far back the hammer is drawn in DA mode. In other words, could something be worn such the hammer is not rotating back as far as it should thereby not getting the full benefit of the mainspring?
308S
