22 Revolver Needs Help

[gmarshall99]

Stop buying CCI ammo; their primers are notorious for being harder than federal, remington, etc.

 

[rck281]

Can you check the headspace with a feeler gauge? (space between the rear of the cylinder and the breechface, ck after a good cleaning and wipe down)
It should be .008"- .010". Smaller is better.

It's between .006 and .008" No noticeable end shake.

Yes, I cleaned out the firing pin hole and checked the spring.
The rounds are being seated firmly. They always seem to fire on the second hit without turning them.

Stop buying CCI ammo; their primers are notorious for being harder than federal, remington, etc.

That's what is on the agenda next. One of my friends is going to trade me some 50 round boxes for some CCI. Going over Thursday to do the trade and then to the range.
I do realize the CCI primers are harder than most and that Federal is preferred by those with much lightened trigger/hammer jobs. However, I think CCI is generally considered the highest quality 22 ammo (outside of some match ammo). I have probably shot 30,000 rounds of CCI through my M41 over the past 50 years. It performs almost flawless and CCI Standard Velocity is the standard for M41s but it won't fire in my M34.

I really down to ammo being the most likely problem.

 

[minconrevo]

The OP says it's a 34 so we have the .22LR problems of dependable ignition to consider. It takes a solid smack of the firing pin to set off .22's. Most any DA/SA revolver will fire dependably on SA; it's the DA function that can get undependable.

With fired cases in the cylinder check the full arc of fire. Do this by holding trigger in and carefully moving the hammer through it's full arc. Should be no drag and a hard smack on the fired case. Look for any hammer to frame dragging. Check to see that the hammer is free but not too free side to side. Make sure the firing pin and it's return spring are clean; perhaps some Gunblaster to remove any gunk. This last thought is a stretch but possible. Has an overtravel pin been inserted in the rebound slide spring?

 

[BC38]

I'm guessing a cut down/weakened hammer spring.

 

[2152hq]

Update:
...
It is improved but not fixed. With CCI ammo it seems to reliably fire in Single Action. About 1 in every 6 rounds doesn't fire in DA shooting. The indentions look the same to the naked eye. The rounds fire when hit in the same spot a second time.

I only had 14 rounds of Aguila but the all fired when shooting DA.

.....

Sounds like the gun just doesn't quite have the strength to fire off the CCI stuff.

 

[Llance]

You know I just had a thought about this; I wonder if the hammer spring tensioner screw is too short, not providing enough tension to the spring. That would surely keep the hammer from providing full impulse to the firing pin. I bought a revolver, .38 spl model 10, that someone had shortened the hammer spring tension screw in an attempt to lighten the trigger pull on the revolver. I cursed the gun for a couple of weeks until I compared the screw with another and discovered the problem.

 

[BC38]

You know I just had a thought about this; I wonder if the hammer spring tensioner screw is too short, not providing enough tension to the spring. That would surely keep the hammer from providing full impulse to the firing pin. I bought a revolver .38 model 10 that someone had shortened the hammer screw tension spring screw in an attempt to lighten the trigger on the revolver. I cursed the gun for weeks until I compared the screw with another and discovered the problem.

It is a model 34-1 J-frame. They don't have a strain screw and flat mainspring. They have a coil spring and hammer strut instead.
BUT, if the spring is weak or has had a coil or two taken off of it (to make the trigger pull lighter) that would have the exact same effect as shortening the tension screw on one with a flat mainspring. It will lighten the trigger pull - but if taken too far it will also cause light strikes.

 

[Llance]

Shows what I know about the mod 34. I seem to remember the op saying he has replaced the spring. It's been more than a few years since I've looked into the inner workings of a "J" frame.

 

[BC38]

Shows what I know about the mod 34. I seem to remember the op saying he has replaced the spring.

By golly he did - I missed that. And a spacer installed under the spring for some extra oomph too.
Hmmn, new firing pin as well.
This one is a real stumper.
Maybe an issue with the hammer/strut assembly? Hammer dragging on the frame? Strut bent or dragging?

 

[biggray]

Hi. I had the same problem with my 34. I tried the nine pound spring from Wolff and it help a little. One other S&W lightweight 22 was listed as coming with a 15lb spring. That sent me to a junk spring box. I found a spring very close in size but longer. I started about 1/2" longer. With that I no longer had double action. I kept cutting a coil off until it came back. It now set off all the ammo I tried but had a very heavy pull. I kept clipping and testing until I had a pretty decent pull and it was firing all the different ammo. I think the spring was the old recoil spring from my Ruger MKI. Hope this helps. My 34 is one of my favorite .22s. Thanks Bill

 

[ironhead7544]

Had a Model 51 years ago. No problem with ignition, but the trigger pull was hell for stout.

You might want to try a mainspring from one of those, if it is heavier.

I take it you checked the firing pin protrusion.

 

[cmj8591]

With head space and end shake in spec, my next move would be to run a reamer into each chamber.

 

[jjfitch]

Surgically clean!!??

To help with diagnosis have you tried this:

After firing a round open the cylinder and manually push each round in as far as they will go. Fire the next round and repeat. If this cures the problem, it points to a cylinder issue.

I have similar issues with my M41's after a couple hundred rounds of CCI SV's! A thorough cleaning including 0000 bronze wool wrapped around a wire brush to clean to "surgical specs" is called for!

Smiles,

 

[AzShooter]

Go to Ace Hardware with your spring and look for one that is sturdier and longer. When I had a coil spring conversion done to my 625 years ago it didn't take much but just a slightly heavier spring solved all my problems.

Another idea is CCI ammunition is harder to set off than some others. I have a very light action on my revolver and it shoots Federal BYOB most consistently as well as Remington Bucket Of Bullets. Federal Gold HV ammo also works 100 %.

 

[robertrwalsh]

I have a 34-1 with a mediocre trigger. I changed the rebound spring and the trigger spring for lighter ones. I got about one misfire per cylinder with any sort of ammo. Put the factory trigger spring back in and it went back to 100% reliability and the trigger was still pretty good.

 

[rck281]

...
With fired cases in the cylinder check the full arc of fire. Do this by holding trigger in and carefully moving the hammer through it's full arc. Should be no drag and a hard smack on the fired case. Look for any hammer to frame dragging. Check to see that the hammer is free but not too free side to side. Make sure the firing pin and it's return spring are clean; perhaps some Gunblaster to remove any gunk. This last thought is a stretch but possible. Has an overtravel pin been inserted in the rebound slide spring?

The hammer moves freely. I also removed the mainspring and reinstalled the side plate to be sure that wasn't causing a problem. Hammer travels freely with no frame contact. Firing pin recess was cleaned with the firing pin was replaced. No overtravel pin in rebound slide spring. (That could possible cause the problem and I didn't think of that. )

Several have mentioned having a chamber reamer run thru the charge holes. When I first discovered this problem, I had that done by a local S&W smith. He then honed each hole with two different grits using Flex-Hone's. Ammo drops in and extracts easily. No need to push them in because they drop in.

Different ammo. Did some testing today. Fired 2 cylinders full of Ammo. The columns are Cylinder Number, Number of Misfires, and DA or SA shooting
Cylinder No Misfires Action

Winchester Wildcat
1 2 DA
2 0 SA
3 0 DA

Remington UMC
1 0 DA
2 0 DA

American Eagle
1 0 DA
2 0 DA

Remington Golden Bullet
1 0 DA
2 2 DA
3 1 DA

Remington Thunderbolt
1 0 DA
2 0 DA

Federal
1 0 DA
2 0 DA

CCI Std. Vel.
1 2 DA
2 0 SA
3 2 DA

As you can see, it's not just CCI but it's the worst. This is with a 9lb mainspring and no hammer block.

Next. Install spacer under mainspring and reinstall hammer block. Retest and end this project!

Thank you to everyone. I really do apprecciate the advice.

 

[rck281]

This will be my last post and I want to say that I really appreciate the suggestions. I have now concluded this repair with the following modifications:
I have replaced the 8 1/2lb mainspring with a Wolff 9lb mainspring and a custom machined 0.080" spacer. The firing pin was replaced with an custom made extended. Endshake was reduced by 0.003"
The results: I fired 18 cylinders full on the ammo listed in the previous post. All shooting was done Double Action.
1 failure to fire with Winchester Wildcat
2 failures to fire with CCI Mini Mag
The remaining 105 rounds fired on the first hit DA.
Everything seems to work SA.
I'm calling it done and am going to avoid CCI ammo in the gun.
Thanks again everyone.

 

[Heinz]

Dick, thanks for taking the time to post all of this information. I will add, I have a Walther P22 that likes CCI minimag's but probably failure to fire about 1% of time
My wife's Smith M17 gets a failure to fire about once per cylinder double action on CCI. NO failure to fire on Eley.