Primer with 2 marks, timing?

[__steve__]

Was doing an inspection on my 500 4”. Gun does need a cleaning but the action failed 4 out of 5 times in both S/DA: In DA the hammer drops before cylinder stop center locks to cylinder. In SA the hammer locks without cylinder locking. Everything else fine.

Is it accurate to assume the primer condition below is a symptom of the timing issue?

http://smith-wessonforum.com/attachment.php?attachmentid=597004&stc=1&d=1665621202

What I am visualizing is the pin drops on the unlocked cylinder making its 1st (shallow) off-center pin dent, sparking combustion which kick-locks the action to center prior to pressure buildup. No?

 

[smithman]

I’m guessing the hammer is bouncing due to inertia and momentum.

 

[JDinAZ]

Was doing an inspection on my 500 4”. Gun does need a cleaning but the action failed 4 out of 5 times in both S/DA: In DA the hammer drops before cylinder stop center locks to cylinder. In SA the hammer locks without cylinder locking. Everything else fine.

Is it accurate to assume the primer condition below is a symptom of the timing issue?

http://smith-wessonforum.com/attachment.php?attachmentid=597004&stc=1&d=1665621202

What I am visualizing is the pin drops on the unlocked cylinder making its 1st (shallow) off-center pin dent, sparking combustion which kick-locks the action to center prior to pressure buildup. No?

When that case was in the cylinder was the off center hit to the right or to the left of center.

If to the left it is firing out of battery early before the cyl stop locks in place just as you have come up with with your timing test failures.

Meaning it’s not carrying up far enough before it lights off

If off center to right then the cylinder is passing the cyl stop then firing.

Do you have also have slap peening at the cylinder notch where the cylinder stop locks into the cylinder. That would be caused bu the cylinder being forced the rest of the way into battery as the bullet exits the throat and enters the forcing cone and tries to align itself to do so. Bad mojo in any revolver much less a 500.

I remember seeing a few 686+ that had slap peening at the cylinder stop from an early timing issue

If so on the slap peening at cylinder notches. Which side of cyl notch is peened. The full height side. Or peened on the two taller points only of the scooped side of the notch.

That said. When you did your da and da timing tests did it fail to carry up far enough. Or did it carry up ok but the cyl stop didn’t lock in place

If is carries up but just doesn’t lock in then it’s probably just some grunge down in the cylinder stop area that needs a good cleaning and it should be fine.

When testing the timing can you roll the cylinder the rest of the way and it locks in. About halfway thru the hammer motion to the rear you should hear and feel a click. That is when the cylinder stop is released into its engagement ready position. After that click you should be able to grab the cylinder with your free hand and rotate it the rest of the way into battery where the cylinder stop locks into the notch in the od of cylinder.

If that works in da and sa actions on all chambers then you definitely have a carry up issue. Not cylinder stop issues.

 

[racoonbeast]

I have heard that some of the earliest versions of this gun had issues with the cylinder not locking up completely. Supposedly the issue was solved by the factory using a more powerful cylinder bolt spring. For the price of one, it might be worth a try.

 

[H Richard]

I think it's time for it to be looked at by a qualified S&W gunsmith or the factory.

 

[cmj8591]

Assuming that your gun is locking up, try a stronger firing pin spring. The recoil inertia is causing it to bounce.

 

[__steve__]

I’m guessing the hammer is bouncing due to inertia and momentum.

I believe this may not be the case as the cylinder stop does not fully seat itself (4 out of 5 times during dry testing) when SA cock’d, and DA when hammer drops. However I am not ruling out anything.

I have heard that some of the earliest versions of this gun had issues with the cylinder not locking up completely. Supposedly the issue was solved by the factory using a more powerful cylinder bolt spring. For the price of one, it might be worth a try.

This area is the first place I am going to inspect. Some crud might be in there, I hope.

I think it's time for it to be looked at by a qualified S&W gunsmith or the factory.

This will be last resort.

When you did your da and da timing tests did it fail to carry up far enough. Or did it carry up ok but the cyl stop didn’t lock in place

If is carries up but just doesn’t lock in then it’s probably just some grunge down in the cylinder stop area that needs a good cleaning and it should be fine.

When testing the timing can you roll the cylinder the rest of the way and it locks in. About halfway thru the hammer motion to the rear you should hear and feel a click. That is when the cylinder stop is released into its engagement ready position. After that click you should be able to grab the cylinder with your free hand and rotate it the rest of the way into battery where the cylinder stop locks into the notch in the od of cylinder.

If that works in da and sa actions on all chambers then you definitely have a carry up issue. Not cylinder stop issues.

I don't see any peening on the cylinder, it's also just over a year old.

Will try the cylinder stop release test tonight, where I roll the cyl after stop release click. I am hoping it carries up fine and there might be crud in there. This started recently.

Thanks, will report back when I hopefully fix it. If not, will have to figure the next step.

 

[__steve__]

Took everything apart and cleaned. Noticed the stop spring was in crooked so I removed and cleaned it. There was also rust there on the frame where the spring contacted, and cleaned it. Spent quite a bit of time then put it back together and STILL BAD.

It just isn’t carrying far enough and think it may be the hand or extractor.

Are the hand and extractor on X frames direct replacements, or do they require a S&W armorer to modify the surfaces?

Also, is there supposed to be an inner pin for the spring stop? I saw an animated video of the X-frame assembly with a pin there, mine didn’t have one.

 

[smithman]

Took everything apart and cleaned. Noticed the stop spring was in crooked so I removed and cleaned it. There was also rust there on the frame where the spring contacted, and cleaned it. Spent quite a bit of time then put it back together and STILL BAD.

It just isn’t carrying far enough and think it may be the hand or extractor.

Are the hand and extractor on X frames direct replacements, or do they require a S&W armorer to modify the surfaces?

Also, is there supposed to be an inner pin for the spring stop? I saw an animated video of the X-frame assembly with a pin there, mine didn’t have one.

Depends if you get lucky. I’ve put an oversized hand in a lazy 629 and it was a perfect fit and timed up perfectly.

 

[Dave Lively]

If it was my gun and under warranty I would send it back to S&W. You have already tried most of the easy fixes.

Most of the complaints I have seen about their service recently involve semi-autos not functioning well with particularly brands of ammo or intermittent reliability issues, not problems that are easily and consistently reproduced.

Have you noticed the gun spitting lead? You could argue that a 500 S&W spitting lead because of a timing issue is a safety concern too.

 

[__steve__]

If it was my gun and under warranty I would send it back to S&W. You have already tried most of the easy fixes.

Most of the complaints I have seen about their service recently involve semi-autos not functioning well with particularly brands of ammo or intermittent reliability issues, not problems that are easily and consistently reproduced.

Have you noticed the gun spitting lead? You could argue that a 500 S&W spitting lead because of a timing issue is a safety concern too.

I’m emailing them now to get an RMA. I’m sure they’ll fix it

 

[__steve__]

One more thing, on occasions the extractor does contact the recoil shield when closing cyl. Is that a problem? I see signs of this happening on my other revolvers, particularly my PC. The cylinder actually touches the forcing cone when closing, so I guide it close with pressure towards the back as the cylinder reaches the barrel. Now I notice a few scratches on the shield.

 

[Protocall_Design]

If the extractor is dragging on the recoil shield, there is usually debris under the extractor, caught between it and the seat in the cylinder. This powder, carbon, lead, or whatever falls on the back side of the extractor when ejecting fired cases. This happens on all brands of revolvers. It's easily cleaned out with a toothbrush. You need to clean both mating surfaces.

If the cylinder touches the forcing cone, you either have major leading, or endshake, or some of both. The endshake needs to be looked at, and maybe better quality ammo.

 

[steelslaver]

Take the cylinder off the yoke and make sure the yoke tube and cylinder center hole are clean. Plus, that your yoke is not moving forward to back in frame. Your cylinder should not be rubbing on the face of barrel extension. I am wondering about endshake and yoke. Big cylinder hanging on that yoke.

 

[JDinAZ]

If the extractor is dragging on the recoil shield, there is usually debris under the extractor, caught between it and the seat in the cylinder. This powder, carbon, lead, or whatever falls on the back side of the extractor when ejecting fired cases. This happens on all brands of revolvers. It's easily cleaned out with a toothbrush. You need to clean both mating surfaces.

If the cylinder touches the forcing cone, you either have major leading, or endshake, or some of both. The endshake needs to be looked at, and maybe better quality ammo.

Take the cylinder off the yoke and make sure the yoke tube and cylinder center hole are clean. Plus, that your yoke is not moving forward to back in frame. Your cylinder should not be rubbing on the face of barrel extension. I am wondering about endshake and yoke. Big cylinder hanging on that yoke.

To add to these gents

There is also a forward motion in the new cylinders. This is caused from the new style yoke screw.

It has a plastic pin with a spring inside. This pin will move fore and aft just a shade. It will allow your whole crane and cylinder to rub the frame under the forcing cone with the crane and the forcing cone itself with the cylinder face.

Not as visible in stainless of steel guns but airweights the mark at the frame from yoke is pretty visible. My 329PD and 438 both show this rubbing from the new style yoke screw tip being able to “wiggle” allowing the assembly to slightly float fore and aft

 

[__steve__]

Go it back from S&W yesterday. For the timing issue I sent it in for, they repaired yoke and replaced trigger. It helped a little but two of the cylinder’s chambers still fail in SA, even loaded with empty cases. Not sending it back again

 

[smithman]

Go it back from S&W yesterday. For the timing issue I sent it in for, they repaired yoke and replaced trigger. It helped a little but two of the cylinder’s chambers still fail in SA, even loaded with empty cases. Not sending it back again

Disappointing…

 

[scooter123]

First off that off center hit is NOT the source of ignition, it's way too off center to trigger that primer. The ignition source is that dead center hit. That second hit is caused by the hammer rebounding during recoil and the cause is because you have the trigger pulled all the way back during recoil. Note, when the trigger is released the hammer block is position to prevent the hammer from contacting the firing pin. Problem is that I don't think it's humanly possible to release the trigger during recoil. Bottomline this is rather typical when shooting full power Magnums.

Note the sequence is as follows, the hammer falls and is stopped by the firing pin, they the gun recoils and carries the hammer backwards, next you control the recoil and bring the gun back on target firmly, then the hammer returns forward due to the mainspring. So, the next question becomes what is kicking the cylinder counterclockwise. The culprit hear is the cylinder stop getting kicked out of the notch during recoil. A problem that IIRC was corrected on the 44 Magnums as part of the "endurance package". I would expect that the 500 Magnum would also have this package but there is a possibility that the factory dropped the ball and used an incorrect and weaker cylinder stop spring when assembling your revolver.

Finally if you are doing that super slow motion carry up test or dragging a thumb while testing for carry up YOU ARE DOING IT WRONG. This methodology is all internet hogwash. The S&W revolver is a Combat Revolver and has clearances that insure that the gun will function properly after being dropped a pool of mud. As a result they will rely on Inertia to carry the cylinder into lock to small extent. Yeah they can be tuned to perfection for this but the downside of doing this will result in a cylinder stop with a tendency to jam if stop and notch aren't perfectly clean.

The final test is the cylinder movement when it's locked by both the cylinder stop and the hand. With an unloaded revolver pull the hammer back to full lock, secure it with your thumb and pull the trigger back completely. Hold that trigger back and lower the hammer slowly. Then test how much movement there is to the cylinder. This movement should be tiny, small enough that you only feel it and don't see any movement visually. That is the ideal for lockup. However if you can see just a hint of movement that is tolerable, what you do not want to see is any movement approaching the thickness of a thin piece of paper.

After reading you initial post I'm thinking that someone prior to you has been poking into your cylinder stop spring and I suspect that your's is weak. As you know it's an easy part to replace and I find it surprising it wasn't replaced when S&W worked on your gun. Because that should be a near automatic response for the issue you have reported.

 

[__steve__]

Yeah
Must be experiencing a lack ability in the repair dept or they don’t care. Who would want to shoot a 500 magnum knowing 2 out 5 are out of battery, and I just mastered the game of flinch control too.

 

[__steve__]

First off that off center hit is NOT the source of ignition, it's way too off center to trigger that primer. The ignition source is that dead center hit. That second hit is caused by the hammer rebounding during recoil and the cause is because you have the trigger pulled all the way back during recoil. Note, when the trigger is released the hammer block is position to prevent the hammer from contacting the firing pin. Problem is that I don't think it's humanly possible to release the trigger during recoil. Bottomline this is rather typical when shooting full power Magnums.

Note the sequence is as follows, the hammer falls and is stopped by the firing pin, they the gun recoils and carries the hammer backwards, next you control the recoil and bring the gun back on target firmly, then the hammer returns forward due to the mainspring. So, the next question becomes what is kicking the cylinder counterclockwise. The culprit hear is the cylinder stop getting kicked out of the notch during recoil. A problem that IIRC was corrected on the 44 Magnums as part of the "endurance package". I would expect that the 500 Magnum would also have this package but there is a possibility that the factory dropped the ball and used an incorrect and weaker cylinder stop spring when assembling your revolver.

Finally if you are doing that super slow motion carry up test or dragging a thumb while testing for carry up YOU ARE DOING IT WRONG. This methodology is all internet hogwash. The S&W revolver is a Combat Revolver and has clearances that insure that the gun will function properly after being dropped a pool of mud. As a result they will rely on Inertia to carry the cylinder into lock to small extent. Yeah they can be tuned to perfection for this but the downside of doing this will result in a cylinder stop with a tendency to jam if stop and notch aren't perfectly clean.

The final test is the cylinder movement when it's locked by both the cylinder stop and the hand. With an unloaded revolver pull the hammer back to full lock, secure it with your thumb and pull the trigger back completely. Hold that trigger back and lower the hammer slowly. Then test how much movement there is to the cylinder. This movement should be tiny, small enough that you only feel it and don't see any movement visually. That is the ideal for lockup. However if you can see just a hint of movement that is tolerable, what you do not want to see is any movement approaching the thickness of a thin piece of paper.

After reading you initial post I'm thinking that someone prior to you has been poking into your cylinder stop spring and I suspect that your's is weak. As you know it's an easy part to replace and I find it surprising it wasn't replaced when S&W worked on your gun. Because that should be a near automatic response for the issue you have reported.

I do not use the finger cylinder drag to add tension during carry-up test, good way to wear out the already burdened hand on this heavy revolver.

The cylinder stop spring on X frames was addressed earlier few years after initial production, but I would be more than happy to buy heftier replacements if I could ever find any.