New 617: Extremely heavy DA pull

[Borderboss]

I just picked up a factory fresh 617-6 10-shot .22. It has to have the heaviest DA and SA pull I've ever had in any revolver. The DA pull must be 15 pounds if not more. It's also very difficult to pull the hammer back to single action. Then the SA pull is heavy, but crisp. I don't feel any binding throughout the heavy DA pull, and with the other symptoms, I'm guessing the mainspring is really heavy in this one, and perhaps the trigger return spring.

I have a Wolff Power Rib mainspring for K-frame laying around, so I think I'll put that in this evening. After that, I'll see if the trigger return spring needs to be changed as well. I plan on using this gun for .22 Steel Challenge, so I need a good trigger pull with reliable ignition.

Have any of you run into this situation with this model? The action has to be a bit different than the norm due to the 10-shot cylinder that must result in a modified action due to the short turn of the cylinder.

Thanks much for any suggestions!
John

 

[armorer951]

The action on the 10 shot revolver is exactly the same internally, with the exception of the hand.

If the heavy pull is purely related to spring tension issues, you might take a look at the mainspring strain screw to see if it is too long. If this is the case, the screw can put too much tension on the mainspring. Many here on the forum incrementally modify (shorten) the strain screw length, or add an adjustable hex screw in place of the strain screw so that they can "adjust" the tension on the mainspring by moving the screw in/out. Substitution of the aftermarket spring you mentioned may also help.

Remember that substituting a lighter rebound spring will help lighten the DA, but will also lighten the SA pull too, so be sure to check the SA pull weight with a pull gauge after any changes with respect to this spring. I believe the consensus here is the 13-14 pound rebound springs give the most consistent results without causing trigger return issues.

 

[Nightowl]

I worked over a 586 a couple of years ago with similar strong trigger pull weights. I didn't measure it, but it seemed to me the new mainspring was thicker than older ones.
It is generally thought that .22s require a harder strike than center fire guns. It seems to run that way, but the last few years, it seems most of the misfires I have experienced have been ammo related, as they fire on the second hit, after the cartridge has been rotated 90 to 180 degrees in the chamber. Some fire, but feel weaker than normal also, making me wonder about ammo QC.

 

[Borderboss]

The action on the 10 shot revolver is exactly the same internally, with the exception of the hand.

If the heavy pull is purely related to spring tension issues, you might take a look at the mainspring strain screw to see if it is too long. If this is the case, the screw can put too much tension on the mainspring. Many here on the forum incrementally modify (shorten) the strain screw length, or add an adjustable hex screw in place of the strain screw so that they can "adjust" the tension on the mainspring by moving the screw in/out. Substitution of the aftermarket spring you mentioned may also help.

Remember that substituting a lighter rebound spring will help lighten the DA, but will also lighten the SA pull too, so be sure to check the SA pull weight with a pull gauge after any changes with respect to this spring. I believe the consensus here is the 13-14 pound rebound springs give the most consistent results without causing trigger return issues.

Thanks much for the comments on this. I put in the extra Wolff "Standard Power" Power Rib mainspring with the factory strain screw, and the pull is extremely good now. I can't say that it'll go "Bang" all the time however. That'll be a test for tomorrow. If I have ignition problems, I do have a couple of extended length strain screws from Wolff that I can grind down to the proper length to get better ignition.

The inside of the gun was also bone dry, which I found odd coming right out of the factory. A good oiling I would think contributed to the change in pull.

I didn't change the trigger rebound spring because I wanted to make one change at a time. If I have reliable ignition, I'll put in the 13lb Wolff rebound spring I have laying around and make sure that trigger return isn't affected. This will be a .22 Steel Challenge gun, so reliability will be needed although my life won't be depending on this gun.

 

[Borderboss]

I worked over a 586 a couple of years ago with similar strong trigger pull weights. I didn't measure it, but it seemed to me the new mainspring was thicker than older ones.
It is generally thought that .22s require a harder strike than center fire guns. It seems to run that way, but the last few years, it seems most of the misfires I have experienced have been ammo related, as they fire on the second hit, after the cartridge has been rotated 90 to 180 degrees in the chamber. Some fire, but feel weaker than normal also, making me wonder about ammo QC.

Thanks much for the comments.

This mainspring seemed thick to me as well. It measured .075" near the bottom at the point the strain screw would impact it.

As to .22s requiring a harder strike, I know I've heard that too but it has never made sense to me given the softness of the case that needs to be crushed for ignition. I seem to recall in the recesses of my mind that decades ago it was noted that the harder strikes for .22s were used because the process of priming a .22 case is such a "haphazard" (my word) process that the heavy strike was trying to make up for that to try to guarantee that the round would light off. I know nothing has changed in all these years relative to the priming process, but I'm willing to bet there's less metal in those cases than there used to be, so therefore easier to light. I guess I'll find out tomorrow when I try it with the new mainspring.

 

[AzShooter]

I've worked my 617 over a lot and have a very smooth DA pull. I use a stock mainspring and lighted up with the strain screw, then use blue Loctite to hold it in place.

I use an 11 pound rebound spring. My fingers are use to this light of a spring. I would suggest a 13 until you get familiar with your gun. The last thing you need is to skip a chamber while pumping hard for Steel Challenge.

If you want the lightest trigger order the NEW Mass Drive Hammer from ApexTactical.com.

 

[slickracer]

I run a Wolff standard power spring in rimfire revolvers to ensure good ignigion.

 

[Doug44]

I have two 617s. There is not much you can do with the mainspring and still get reliable ignition. Have an action job done and go to lighter trigger return spring. S/W revolvers require very little lube. You can also try a longer firing pin.

 

[Borderboss]

I have two 617s. There is not much you can do with the mainspring and still get reliable ignition. Have an action job done and go to lighter trigger return spring. S/W revolvers require very little lube. You can also try a longer firing pin.

That's depressing to hear. I haven't tried it yet with the new mainspring but it sounds like the momentum of that heavy hammer still won't be enough to light the rimfires. The trigger pull was completely unusable as it came from the factory. It sounds like this will be a project gun.

 

[Doug44]

How about an update. Hope you made some progress.

 

[studenygreg]

I just got a NIB 617-6 last weekend. DA was 12 lbs and SA was 7lbs. I got WC spring kit that I have had good success with in other models. Installed it today. DA is 8lbs and SA is 4 lbs with the strain screw bottomed out. I bought a longer screw in case I need more tension. I will try to make it to the range this weekend to test it out.

Sent from my SM-G960U using Tapatalk

 

[Borderboss]

How about an update. Hope you made some progress.

Sorry Doug. I haven't made it to the range yet to test it out.

I think before I go to the range, I'm going to grind down one of the extra long Wolff mainspring screws so that the OAL is the same when taking into account the grove in the Wolff mainspring. This will put a little more oomph into the spring without too much of a detrimental affect on the new trigger pull.

I also found a 13lb trigger return spring laying around, so I'll put that one in too.

 

[pasound]

I bought my 617 spring of last year. It too had an abysmally heavy and stiff DA pull. Several sessions of 2-300 rounds per at the local indoor range smoothed things out. It's still heavy, but is now smooth and no longer drags. At this point it seems appropriate for a .22 that weighs more than any big bore revolver in my collection. It shoots one hole groups off a rest with nearly any decent .22 ammo I put in it.

 

[Borderboss]

I've finally gotten back to dealing with my 617 after all these months. I finally fitted the Wolff extra long mainspring strain screw, and installed the Wolff 13 pound trigger return spring. While I was inside the gun, I did some polishing of the surfaces of the trigger rebound slide and the corresponding surfaces in the frame. Then a bit of oil in all the right places. The results were excellent, a great double action and single action pull where the gun goes bang.

I installed the ADE Optics red dot reflex sight on top of the Weigand Short Mount. It feels great. I should be ready for the upcoming Rimfire Steel Challenge season.

 

[AzShooter]

I shot mine this weekend for our monthly Steel Challenge Match. I had fun but had a few problems with ignition. My trigger pull is 7 pounds double action.

I've done a lot of polishing, tuning and changing springs. I also now have an Apex Tactical Mass Drive Hammer. They advertise a 6.5 pound trigger pull that is reliable. I've tried it with a variety of rounds and they are correct.

I changed out the mainspring for a Wolf and replaced the 11 pound rebound spring with a 12 pound because I out ran the trigger a few times. I didn't get my finder off the trigger all through the shot.

I also put a Cylinder And Slide extra long Firing Pin and Spring Kit in.

I set the trigger pull to 8 pounds for my satisfaction and will be testing Wednesday to see how it works. I'm using Federal 36 grain bullets and want to make sure they all go boom. One nice thing is that even after 200 rounds the cylinders are clean and I don't have to run a brush though them. I carry an electric drill with a nylon brush just in case I start getting hard extractions.

I also use DS-10 Speed Loaders. They are the best out there. Others have copied them but don't have the reliability. Over the years I've won 15 off the prize tables so that and a few loading blocks get me through the matches.

 

[elpac3]

Thanks much for the comments.


As to .22s requiring a harder strike, I know I've heard that too but it has never made sense to me given the softness of the case that needs to be crushed for ignition. I seem to recall in the recesses of my mind that decades ago it was noted that the harder strikes for .22s were used because the process of priming a .22 case is such a "haphazard" (my word) process that the heavy strike was trying to make up for that to try to guarantee that the round would light off.

The priming process for .22 rimfires is different than the process for making CF primers. In the case of rimfires, the cases are put onto a spinner and the ball of priming mix is dropped into the case. The high speed spinning (several thousand RPM) moves the priming mix out into the rim area. After that, the cases are dried so the moisture is removed from the priming mix rendering them shock sensitive.

The issue with RF priming is there can be voids in the rim where the priming mix did not get to and hence will not ignite when struck. If the moisture content in the priming mix is on the low side, the mix will have problems distributing (not flow evenly) into the rim area. Hence the reason rotating the cartridge slightly will generally result in positive ignition is you are hitting a primed area in the rim.

Conventional primers on the other hand have a pre-shaped priming mix charge inserted into the priming cup before the anvil is inserted which assures there are no voids in the distribution of the priming mix.