Service Six Revolver Jams after Recoil

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Durango Dave

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I have a Ruger Service Six that jams up after recoil. I think that when the gun suddenly jerks backward something (maybe a pawl or arm) moves forward too far causing it to jam.
Trigger assembly (Large).jpg

When I say jam I mean I can't cock the hammer, whether I try double action by pulling the trigger or single action by cocking the hammer, I can't shoot the next round. The fix is as easy as pointing up and then I can cock the hammer single action mode.

It doesn't take much recoil but I do know recoil causes my problem. If I load up 6 rounds it never jams on the first shot. It doesn't happen every time but it can jam after every shot. After shooting all 6 rounds it may jam on the 7th shot. That shot is a spent shell but this tells me that it is happening after the recoil of each shot.

I know it's not the cylinder latch because I can see it move out of the way as I try to cock the hammer.

This may be the type of problem that no one, not even a Ruger gunsmith, could fix over the internet but I thought I'd ask.
 

weaselmeatgravy

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Check the extractor rod and confirm it is fully tightened down. There is a spring loaded plunger in there that pushes back on the transfer bar. If the transfer bar is not clear of the rear sight, the gun won't cock. And if the extractor is a turn or two loose, it may not always push back far enough. And tipping the gun up will cause gravity to assist with getting the transfer bar out of the way.

Power residue or other grime under the extractor star is another thing to watch out for, but the symptoms of that are usually along the lines of the cylinder not wanting to open.
 

Durango Dave

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My extractor rod is not loose but I do see that it is bent. I looked into this a bit more. The extractor rod has a pin that pushes out the back of the cylinder. This spring loaded pin pushes into the cylinder release. If the cylinder is released you can't pull the trigger or cock the hammer. I took my Ruger out to shoot. My thinking is when my revolver jams I wanted to check to see if the cylinder release button was becoming partially depressed. That wasn't the case.

Back to the drawing board.
 
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Check for any gunk in or around the pawl spring. If the spring is not forcing the pawl back far enough when you release the trigger it may not be being pushed back through the frame through the window which allows it to contact the star and it will bind against the frame.

This may also seem trivial but make sure you are allowing the trigger to go fully forward before attempting to fire the next round. With a full cylinder that you just loaded it is fully forward and you did say that it never jams on the first shot.
 

Durango Dave

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Thanks. I've cleaned the pawl and other parts. I've had this gun for a year and have cleaned it often. It has never shot reliably.

While the symptoms are similar to short stroking the trigger this is not the issue. Once the gun jams I can completely remove my finger from the trigger, then try again to pull the trigger. It won't move. Nor am I able to pull the hammer back even with my finger off the trigger. The gun is truly jammed and will not shoot. I then point the gun skyward (sometimes I give the gun a slight downward jerk) and cock the hammer single action style and can shoot.

To reliably shoot this revolver I must point it upward and cock it single action mode before each shot. I then aim and shoot.
 
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Just throwing things out to be checked.

Take it apart and check the window where the pawl comes through for any burrs. Then install the trigger group and try firing it (push in the cylinder release with a punch) and watch he action of the parts. Then put the cylinder back in and with the hammer removed watch down where the pawl and transfer bar is and look for any abnormalities. Also, try loosening the cylinder release pivot screw by 1/2 to 1 turn. It is possible the screw is not allowing the release to go completely rearward when the cylinder is closed.

Also when you say you clean it often, have you actually removed the pawl and the pawl spring from the trigger and cleaned the opening for the pawl spring? It can get stuff down in there which can make the spring not work as it should.
 

weaselmeatgravy

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I was thinking about this last night and realized my first response was off base. I was mixing up SA and DA transfer bar actuation. Sorry for the misdirection.

The -Six DA was the first Ruger to use a transfer bar and the whole gun was designed from scratch, so the transfer bar is actuated within the trigger group. The New Model SA guns were then a puzzle for the engineers as to how to actuate a transfer bar and they accomplished it with a spring-loaded plunger in the base pin.

The plunger in the DA extractor mechanism only serves to lock/unlock the cylinder.
 

Durango Dave

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Take it apart and check the window where the pawl comes through for any burrs. Then install the trigger group and try firing it (push in the cylinder release with a punch) and watch he action of the parts. Then put the cylinder back in and with the hammer removed watch down where the pawl and transfer bar is and look for any abnormalities. Also, try loosening the cylinder release pivot screw by 1/2 to 1 turn. It is possible the screw is not allowing the release to go completely rearward when the cylinder is closed.
I've tried pushing on the pawl and transfer bar with a narrow rod but I can't recreate the problem.

Also when you say you clean it often, have you actually removed the pawl and the pawl spring from the trigger and cleaned the opening for the pawl spring? It can get stuff down in there which can make the spring not work as it should.
Yes, that pawl and pawl spring seem to be working fine. They move smoothly.
Same for the transfer bar, although there is no spring there.
I'm having a hard time seeing how these could be sticking.

The plunger in the DA extractor mechanism only serves to lock/unlock the cylinder.
True. The plunger in the DA extractor presses onto the cylinder lock. If the cylinder is not locked you can't cock the hammer or press the trigger.
But this does not seem to be the issue. When the gun is jammed up, the cylinder lock button is fully out where it should be.

It's odd that simply pointing up caused it to free up and allow me to cock the hammer. It's something that gravity can easily pull back to the "normal" position.
 

weaselmeatgravy

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It's odd that simply pointing up caused it to free up and allow me to cock the hammer. It's something that gravity can easily pull back to the "normal" position.

Yes, and that is a classic symptom of a transfer bar hangup on a NM Blackhawk which is why I started down that road before actually thinking about it 🤨
 

Ruger00fan

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Is there peening on the transfer bar?
Also - what is that extra layer on the hammer? It looks like someone tried to re-build up that area.
 
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There is only 1 piece that gravity can easily affect, the transfer bar, the other parts are activated/deactivated by other spring driven parts.

I would next pull the hammer out and using a small flashlight, first look at the position of the pawl and transfer bar. Then work the trigger and watch the pawl and transfer bar to see what is happening. The finger off the trigger, rotate the barrel down 90 degrees from horizontal and watch what the pawl and transfer bar are doing as you rotate it down. Then rotate it up to 90 degrees above horizontal and again watch what the pawl and transfer bar are doing.

Also, when you have it all apart, look closely at the area where the hammer, pawl and transfer bar are located, look for any burrs and that the pawl window is a nice clean rectangular shape. While you're at it, look at the pawl from the rear and the transfer bar from the side just to make sure they are not bent in the slightest.

When you are all done with that, put it back together and rotate the cylinder out of the frame (or just take it out). You should not be able to pull the hammer back SA or DA. Then take a small punch and start pressing in on the cylinder release pin as you are trying to pull the trigger. You should not be able to pull the trigger or work the hammer until the safety extension of the cylinder release button completely clears the top of the pawl.

These are just things that I would do if I had the gun in hand - I want to see what the parts are doing in relation to the other parts as they are moving.
 
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'ruger00fan',,,if you are talking about the top front that extension is what actually puts the pressure on the 'transfer' bar to allow it to push the firing pin forward, the notch (space) below it, is for the transfer bar to NOT go up to transfer, thus 'blocking' it,. like S&W calls theirs a "hammer block" the .....the trigger does the "moving" of the bar into position, ergo if your finger is NOT on the trigger, it should NOT fire, the 'bar' drops faster than the hammer can fall??? ( nah ,not really its just out of the way already):cool::rolleyes:;)
 

Ruger00fan

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'ruger00fan',,,if you are talking about the top front that extension is what actually puts the pressure on the 'transfer' bar to allow it to push the firing pin forward, the notch (space) below it, is for the transfer bar to NOT go up to transfer, thus 'blocking' it,. like S&W calls theirs a "hammer block" the .....the trigger does the "moving" of the bar into position, ergo if your finger is NOT on the trigger, it should NOT fire, the 'bar' drops faster than the hammer can fall??? ( nah ,not really its just out of the way already):cool::rolleyes:;)

Regarding his transfer bar, it looks like there might be some interference with the frame on the hammer right around where the top of the transfer bar rests. If the left side of the transfer bar (as installed in the gun pointing forward) also interacts with a protrusion on the frame there, it can become hung up. What is confusing me is that if the transfer bar is locked up somehow, then the trigger wouldn't reset/move either.

Look closely at his picture of his hammer, it looks like someone added a single action cocking notch.
 
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That hammer is of the correct configuration, remember on a DA revolver the hammer can be cocked as a SA so it needs the cocking notch. If the revolver was a DAO (double action only), then you would not see the SA cocking notch, Ruger does not machine the SA cocking notch into the hammer on their DAO revolvers (and there is no hammer spur on a DAO)
 

Ruger00fan

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Interesting. My hammers all don't have that folded over metal that both your hammer and his hammer seem to have.

Update: Interestingly, the hammer in Kuhnhausen's Shop Manual Vol. 1 page 81-83 seems to have the same lip.
 

Durango Dave

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I've been going over this again and again and again.
Dry firing.
With the hammer removed I used a small allen wrench to push and pull on the pawl and transfer bar.
The only time I can get it to jam is if I pull back on the pawl so it hits the bottom of the cylinder lock.
One thing that doesn't make sense is why would I be able to cock the hammer if I point the gun up? :unsure:
In this picture I moved the transfer bar back out of the way. I can pull the pawl back so the top right corner hits the cylinder lock.
I am almost tempted to file that corner down.
Trigger  assembly (Large).jpg
 

Durango Dave

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I shouldn't have to file anything. If I'm on the right track I'd think the pawl or it's spring were sticking. When I take out the trigger assembly the pawl seems to work very smoothly.
How's it sticking? Also when I have the problem I can completely remove my finger from the trigger and try again. It's still jammed. I don't see how the pawl could stay under the cylinder release.
I'm confused.
 
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