My brother has a smith in 36-1 that wont lock up tight.

[super6]

As the title says, What do the gurus say is the fix?

[36g]

Could be worn notches in the cylinder, a weak/broken cylinder stop spring, or a worn cylinder stop.

[Rapier]

Suggest you or your brother take it to a competent S&W revolver gunsmith and get it repaired correctly. A DA revolver rarely has just one thing wrong if it will not lock up correctly.

[Sasquatch-1]

Have you taken off the side plate and cleaned it thoroughly? It may just be dirt and lint.

[freakonaleash]

Probably broke.

[rintinglen]

There are several possibilities: a worn or broken hand, or bolt; a broken or missing bolt spring; or worn or damaged cylinder locking slots. But I would first look to cleanliness. Back in my abortive venture into becoming a gunsmith, I "repaired" at least half a dozen malfunctioning firearms through the simple expedient of giving them a thorough cleaning followed by a proper lubrication of the moving parts.

What I would recommend in this case depends on your level of skill and knowledge. But if you have a basic understanding of tools, here's what I would start with. There are several videos on line showing how to disassemble a S&W revolver, I'd watch them all while assembling a small set of tools, specifically a set of properly fitting screwdrivers, a pair of tweezers and a decent pair of needle nose pliers.

Then I would proceed as follows: remove the grips and the side plate and then the cylinder and crane and soak the whole in a pan of mineral spirits with a lid. I'd let it be overnight, or maybe over several days, letting the mineral spirits dissolve the accumulated dried oils and crud that are present. I'd turn on the video that made the most sense to me, and then I'd go to it. With a pair of nitrile gloves on, I'd take apart the action, carefully managing the hammer spring assembly and rebound slide to avoid launching any springs or parts into orbit. As I removed each part or assembly I'd plunge them back into the pan to soak some more. Then I'd take an old tooth brush and scrub every nook and cranny, periodically slushing the frame back in the mineral spirits to remove debris and dirt. When the frame was done, I'd lay it on an old towel or rag to dry and then clean the smaller parts. When all are clean and dry, I'd take them outdoors and spray them good with brake or carburetor cleaner, wiping them dry with a paper towel or napkin. Then I'd use a Q-tip to lightly oil the contact surfaces with any old gun oil I happened to have at hand and reassemble the gun as per my video, then I'd try it out. Chances are fair to middling that you will have "fixed" the problem. And if not, well, any gunsmith worthy of the name will be glad to repair it and will appreciate having a clean gun to work on.

[Der Gebirgsjager]

What do you mean "won't lock up tight"? The cylinder won't lock into the frame, or the cylinder chambers won't align with the barrel, or that the cylinder locks into the frame but wiggles side to side?

DG

[super6]

All good info, The cylinder will lock up, But has about .015 travel back and forth. Am thinking as 36g suggested, The location pin and index gear on the ejector rod may be worn. And dirt, Weak spring?

[super6]

And thank you Rintinglen, I will check all the vids! My brother is a tool and die maker I am a machinist. This pistol was used by our dad who was a leo and was a leg holster back up. He passed away 12 years ago on 9/11 We just want to get it back right in his memory.

[rintinglen]

Super 6, that condition is referred to as end shake and it is cured by inserting shims into the ejector rod well of the cylinder (Power Custom and Triggershims.com both make them.) Larry Potterfield has a good video on installing them that is available over at Midway USA.

If there is actually .015 slop, you may end up having to remove the barrel, and face off the rear of the barrel shoulder enough to turn the barrel in one more turn. It is simple machine work, though barrel removal tooling gets expensive. I believe Brownell's carries the frame wrench and inserts for this. I would check on line for a video for this.

[slughammer]

All good info, The cylinder will lock up, But has about .015 travel back and forth. Am thinking as 36g suggested, The location pin and index gear on the ejector rod may be worn. And dirt, Weak spring?

I don't think we all understand the potential issue you are referring to.

You say "back and forth" , but then talk about the index gear on the ejector rod???

Back and forth (forward/aft) as you are aiming the gun at a target. This is called Endshake. Could be the yoke/cylinder relationship as Glen talked about.

Rotational left/right, as you are aiming the gun at a target. This is cylinder notches, the cylinder bolt (in the bottom of the frame). And the rectangular cutout in the frame.

Linear Left/Right, as you are aiming the gun at a target. This is the center pin, centerpin hole, extractor rod, extractor rod and/or locking bolt.

How much experience do you and your brother have with S&W revolvers? What you are seeing on a Double Action revolver may be a non-issue or....maybe it is.

Tell us which condition of these three you have and we can help you get deeper into checking and accepting vs checking and correcting the issue.

Sent from my SM-G781U using Tapatalk

[Char-Gar]

This post is like a fellow calling up a mechanic and saying "my car is not running right, how do I fix it?".

[super6]

It is rotational slop, NOT end shake. A yes, We are not gun smiths, Given That fact WE are searching for a starting point. So far I have seen some good info here. Please pardon the parts verbage as I said NOT a smith.

[slughammer]

How much experience do you and your brother have with S&W revolvers? What you are seeing on a Double Action revolver may be a non-issue or....maybe it is.

Do you and your brother have only this one Smith and Wesson DA revolver?

Rotational play is normal; if you're not shaving lead, this may not be an issue.

My 686 has been shot fast DA a bunch. The cylinder stop cutout is peened (the rectangular window), it has plenty of rotational play. The forcing cone takes care of the misalignment and the revolver does NOT shave lead.....all is well.

Sent from my SM-G781U using Tapatalk

[Harter66]

I almost made a very expensive mistake on a Colt 1917 .

Take the grips off and submerge it in a cake pan of your favorite solvent for an hour or 2 then cycle it submerged 10-15 times . For gawds sake unload before you put it in the bucket. Flip it over repeat in all possible axises . Take the cheapest junk lube on the shelf at Walmart that's kind of like WD-40 and stick the straw everywhere it'll go and spray it full . If it runs out any color other than what went in start back a fill a cake pan . I washed a full teaspoon of mud , sand , gunk , and carbon goobers out of that pistol . Turns out the was lead and carbon impacted so much so that the barrel extension actually has a gap between it's top and the top strap and and exposed thread inside the frame .

When in doubt wash it out. K I S S . There's a 50% chance it's gunk not wear causing the problem.

[gwpercle]

This post is like a fellow calling up a mechanic and saying "my car is not running right, how do I fix it?".

LIKE LIKE LIKE !!!
Gary

[super6]

Well, Problem solved. The cylinder locking lug was not returning fully to the top its travel, Sticky grime and dirt were hindering the travel. Cure was brake cleaner and fresh oil! I now have rotational movement of .003" Good to go! Thanks to all who had constructive Info.

[super6]

I almost made a very expensive mistake on a Colt 1917 .

Take the grips off and submerge it in a cake pan of your favorite solvent for an hour or 2 then cycle it submerged 10-15 times . For gawds sake unload before you put it in the bucket. Flip it over repeat in all possible axises . Take the cheapest junk lube on the shelf at Walmart that's kind of like WD-40 and stick the straw everywhere it'll go and spray it full . If it runs out any color other than what went in start back a fill a cake pan . I washed a full teaspoon of mud , sand , gunk , and carbon goobers out of that pistol . Turns out the was lead and carbon impacted so much so that the barrel extension actually has a gap between it's top and the top strap and and exposed thread inside the frame .

When in doubt wash it out. K I S S . There's a 50% chance it's gunk not wear causing the problem.

This will be be the next step. And no it ain't broke LOL.