Endshake on S&W 29 and 686+

[bczrx]

Endshake on S&W revolvers should be under .003", correct?


I have two revolvers that I have measured and which need to be fixed. I'd like your input as to if I am on the right track or if I should change the shim/bearing thickness I am considering ordering from TriggerShims dot com.


29-2:

• Forward measurement of .0015". Rearward/thrust measurement of .011". Total endshake of .0095".
  
• Plan: install .008" shim/bearing, leaving around .0015" of endshake.
• Or, should I shoot for a .009" shim and leave only about .0005" of endshake?

686-4+:

• Forward measurement of .006". Rearward/thrust measurement of .011". Total endshake of .005".
  
• Plan: Install .004" shim/bearing, leaving .001" of endshake.
  
• Or, should I shoot for a .005" shim/bearing and leave no measureable endshake?

686-4 + is a 3.5" barreled PC Lew Horton special [with compensator port at tip] from 1996. It was having some issues with ignition on one brand of ammo. Shimming cylinder to rear should help this. BUT, this would leave a BC gap of .010-.011". This is within modern S&W specs of under .012", but seems large.

Any concerns?

Should I instead ask S&W to turn barrel down and reinstall to reduce gap and take up endshake at same time?

What are your thoughts?

 

[Protocall_Design]

S&W will tell you they are in spec. Sending them a gun is futile. Shim to leave a thou. or so. It needs some clearance to run.

 

[shawn mccarver]

If you send it in, S&W will not, as I understand it, ever use shims to adjust end shake. If you want to pay for the repair, they will set end shake at whatever you want using the factory method. However, if you expect it under their lifetime warranty, they may not adjust end shake if it is within their specs.

 

[stansdds]

I think 0.004" end shake is the maximum for center fire magnum calibers. Shims definitely work, but S&W will not use them. They will stretch the yoke and reface it. You really do need a small amount of end shake for smooth operation. 0.001-0.002" is ideal.
As far as I know, 0.012" is S&W's maximum for acceptable barrel-cylinder gap.

 

[steelslaver]

29-2 install .008 shims
686-4 install .004

I want to have a minimum of .001 and a max of .003. But, I doubt .004 being a problem

I like the shims better than stretching the yoke tube. You are in effect installing smooth hardened races between the 2 surfaces.

 

[bczrx]

Hi All,

As for barrel/chamber gap, I am ok with .011, IF IT DOESN"T SPIT LEAD.

I would prefer .003-.006", but don't mind larger. It is the endshake moving between .0015 and .011 that concerned me.

As for endshake, from all that was said here I went ahead and measured my revolvers then ordered cylinder shims for those that needed them [and a few other shims for my Ruger GP100/SRH]. I will hold off on trigger/hammer shims for the S&W revolvers until all the other shims are completed.



However, we'll see if I need to use them with the 29-2.



I emailed S&W over the weekend regarding if they still do the 'endurance package' for the 29-2 revolvers.

Got a response this week: "yes, we can do that."

I got them to set up a RMA for the endurance package and it is on its way.

They said 6+ months for Performance Center work, so we will see what happens.​

I asked them in the letter I enclosed about the endshake and listed my measurements.

If the endurance package involves fitting a new crane/yoke [with higher heat treating] I would assume they'd adjust the endshake to within internal S&W specs- and I would be surprised if it is .009 again.

If they don't replace the crane/yoke, I asked them about having that fixed. I can always shim it if they don't do it, but it will be at S&W anyway.​

I was surprised that they said 'yes' to the endurance package upgrade.

Of course the first person to email me about this also confused me by discussing the Master Revolver Action Package service and price in the follow-up email.

My response asked for clarification about that vs the Endurance Package as I didn't ask for the MRAP, nor do I need it. My internals are already stoned/polished and slick as is reasonable.

The response to my response was from a different person, who apologized for the confusion and confirmed that the RMA was set for the endurance package upgrade - not the MRAP.
​

Once it arrives on the gunsmith's workbench and the gunsmith calls I'll see what they really are doing.

I am just hopeful that the endshake will be gone when it gets back.


Now, the 686-4+ I ordered the .004 shim for and plan on completing myself.

I also looked for the yoke end surfacing tool, but it is out of stock at Brownells right now, so I'll need to hold off on that for now.​

Thanks for all the advice everyone!

 

[bczrx]

Update.

Just got revolver back from S&W. I called and they said they could do the Endurance Package.

I asked a few different ways and they said yes- they can do it.

Sent it in and also put a request to fix cylinder endshake.

Was told it would be 8 months before they could get to it.

UPS just delivered it today- with no email or call.

Bad news- No Endurance Package, as they had no parts my revolver would need.

Good news- they fixed the endshake and mailed i back without charging me!


I had planned on asking them to reset the barrel-cylinder gap to around .004-.005, but couldn't as it got into my hands before I could request the service.


Overall I am happy. Got it in 8 weeks instead of 8 months. Just wish they had informed me they didn't have parts for my 29-2 before shipping it in.