Action Binding - One Cylinder

[LJA]

First - thanks to the 500 Magnum Nut for being so helpful. Reading a lot of your posts has been good for my budding attempts to smooth-up the actions on my S&W revolvers. I am fairly accomplished in the 1911 trigger-job world, but never had the cajones to remove a side-plate from a revo. Too late now. Watched Jerry Miculek's action-job video and got motivated. The first attempt was on a 686+ - and it went great (except for not reading 500 Magnum's sticky first about not removing the hand from the trigger) after I finally got the hand re-installed. A Wolff spring kit and the action job have left me with a really nice feeling and shooting carry-gun that holds 7 rounds of 357 Magnum.

The next victim of my attentions is a Model 29 3" ported 44mag Performance Center vintage 1990. All good except I notice a distinct resistance or "bind" with one cylinder when cocking the gun single action. The action job went well and the gun is really smooth except for one of six cylinders. I am guessing there is something going on with the ratchet, since the timing is spot-on with all cylinders, but thought I would ask for some advice and expertise before touching anything else.

Thanks in advance! LJA

 

[Nightowl]

If it is right at the end of the single action pull, it is the hand binding on the ratchet. The ratchet needs to be trimmed a bit. That is a delicate operation that you need some instruction on and be careful. I am not the best with tools, so its my least favorite thing to do. If you have a tight barrel/cylinder gap and some endshake, it could be that the cylinder hits the barrel on one chamber. Does not happen very often as cylinders on later guns are pretty square.

 

[LJA]

Thanks NightOwl - the binding occurs about a third of the way or a little less into the cycle - so it may not be the ratchet. The ejector rod seems to be true, so it could potentially be an out of square cylinder. I guess I need to slip a feeler gauge between the end of the forcing cone and cylinder and see what happens when the cylinder rotates - but it seems odd that this would only effect one cylinder.

 

[500 Magnum Nut]

I'd double check your extractor rod. Just a little run out could drag the yoke and cause this. Also if the endshake is too tight, it will do this too. If it's the endshake, trim the yoke a thou and it will fix it up.

 

[LJA]

Thanks - there is no "end-shake" - the cylinder is tight - no fore / aft movement at all in lock-up.

Which way does the ejector rod unscrew in the pre-MIM but later model S&W'S? Clockwise or the other way? I think i need to remove it to really see if it is concentric.

Thanks for taking the time! LJA

P.S. - This is a Perf Ctr gun which doesn't necessarily mean they did anything to the action! Also - the cylinder spins freely when moved out of the frame and the end of the ejector rod really doesn't appear to wobble - but if I push the ejector rod in just a little and turn the cylinder it binds.

 

[500 Magnum Nut]

Clockwise removes the rod. Add cases in the chambers before unscrewing or tightening the rod.

But, I wouldn't take it apart. It won't help you this time.

Fix the zero endshake,
Remove the yoke screw. Slide yoke and cylinder off the gun. A tool is best, but a file will do. Hold it square and remove material from the end of the barrel. Go easy here!
Reassemble, now you will have .001 endshake.
See the faq above.

Here is the tool mentioned

This is the barrel where you trim

 

[LJA]

Thanks - I did a little fling on the end of the barrel and it may have helped some - but there is still a feeling of resistance or binding with one cylinder moving into position. The resistance is more apparent later in the cocking cycle than I originally thought. I'm a little hesitant to remove any more material from the lug barrel since it seems like the problem would occur on more than one chamber moving into firing position. Any further thoughts? Any way to check and see if it the hand/ratchet causing the problem? Thanks!

 

[500 Magnum Nut]

Get a feeler gage and set the endshake to .001-.002 inch.

Once this is set, make certain no part of the ejector rod is rubbing on the yoke. If it's out this needs to be corrected.

Then the last place is to check the ratchet in question. Place fired cases in the chambers to help align the extractor. Use a magic marker and make sure you looking at the correct ratchet. Using a stone or small file dress the offending ratchet mataining the same angle. Remember metal removed is gone for good so go easy here!

Test it and lightly dress it again if needed. Going too far will alter the carry up, so take .001 or so at a time. Nice light strokes.

It should be better. A old trick it to dryfire it some, this will break it in too.

Have fun.

 

[LJA]

Thanks again - you are terrific. The endshake is set properly - so I took a closer look at the extractor - and contrary to rough observations previously performed, it does appear that extractor rod is bent and not rotating concentrically - and thus could be binding in the yoke. How best to straighten it? LJA

Added: The extractor is fine - I took it apart and rolled the various parts on a flat surface - no bend or run-out. So, could you help this revolver smithing newbie figure out which lug on the ratchet is the one associated with the binding cylinder in relationship to the chamber that binds going into firing position? Thanks

 

[500 Magnum Nut]

I use a lathe and indicator. I keep the runout at .001 indicator reading. You could use a drill press and a good eye too.
Take the ejector apart following the safety precautions already mentioned, rotate the rod in the spindle/chuck and tap the high spot over with a lead (Babbitt hammer) or brass or plastic hammer. It's got to be softer that the steel ejector rod or you will dent it. Use care that you don't dent the knurl at the end of the rod.
Sometimes the threaded portion of the ejector is bent and that needs to be bent over and straightened.
Tighten it up will a tool (not your fingers) and check your work. I found once, the collar was not straight so this needed to be filed flat, and that corrected it.

Sometimes it is annoying to do, but it can be corrected.
You will like it when it's fixed.

 

[H Richard]

You seem to have found your problem, but one possibility for bind at one chamber position not mentioned yet is foreign object under extractor star. I had a similar problem some years ago, and thought I had cleaned it properly, but found a single kernel of (unique) powder hidden under the star, and that was the problem.

 

[LJA]

Thanks for the help. I need to take the gun apart (again) and watch the different parts interact - while I think the binding I've been seeking help with is less, it isn't gone. So, I want to make sure that the remainder of the moving parts are properly stoned and fitted to try and isolate the problem. I also feel kind of a grittiness when the hammer is cocked single action that occurs just before the single-action sear engages. I may also try a Wolff hammer spring to see if spring bind or stacking could be part of the equation.