Revolver hand ratchet interface issue

cwalter · #1 10-24-2021, 02:27 AM

I have a 460 that has an issue where the hand is digging into the ratchet when the gun is cocked. It appears the gun is what would be called overtimed? On one charge hole I've seen the cylinder jump to the cylinder stop sooner that what would have been considered normal. While cocking it feels like the hand is binding against the ratchet. I've sent the gun back to s&w and it came back with the same problem. The gun is low round count. Less that 100 rounds through the gun

The question is what causes this to take place when the gun didn't have the issue before. Does overtiming sound like the concern here. I've included a photo of the damage.

What would it take to resolve this issue? I'm in the business of building motors and transmission so small details make sense to me but just need someone with more experience to give me an opinion and direction to go off of. Much appreciated

dsf · #2 10-24-2021, 04:12 AM

Using the "about 10 o'clock ratchet" and chamber for reference the longish drag line on its face is caused by the front of the hand, powered by the hand spring, riding against the the cylinder. Not a bit deal.

The cylinder locks up by the left side of the hand, held laterally in place against the ratchet and in its slot in the frame. The hand and ratchet are probably each a bit proud and should wear in. Not unusual for newly made Smiths. Such is the precision of CNC

If you cock the action with the cylinder swung out (hold back the thumbpiece) you'll see the nose of the hand poke out of its slot. A push on it will show the tension it's under.

Bill Lear · #3 10-24-2021, 04:29 AM

Has the side plate ever been off or the action parts removed by anyone other than S&W?

On S&W revolvers the cylinder stop is cammed down as the trigger is pulled and only briefly. This allows the stop to snap back up under spring pressure and ride along the cylinder surface until it snaps into the cylinder stop notch. The rationale for this is that it's better to have some signs of visible drag and finish wear on the cylinder with a positive lock-up than to attempt the "thread the needle" to hold the stop down until the relatively short lead scallops rotate over the stop, because a fast-moving cylinder can spin faster than the stop can engage.

The biggest problem I've found on the 460 XVR is the cylinder is quite heavy - much more so than on the 500 due to the smaller chambers, making it much more likely to fail to carry up if the gun is cocked slowly, but works fine when the gun is cocked swiftly, especially with cartridges in the chamber to add even more mass.

What you may be experiencing is the hand's leading edge is not quite "broken" enough to smoothly transition from pushing directly against the ratchet, to moving up alongside it at full cock.

When you look at the hand, on the top left edge you should see a slight bevel. If there is no bevel, the revolver will seem to "halt" or stutter as the cylinder rotates, and the key is to have just the right amount.

The first thing I recommend you do is apply Vaseline to the ratchet - just slather it on, then work the action a few dozen times to see how that feels.

The monster X-frames work best with a rapid cocking action to use some of that cylinder inertia to help it carry up and into lock without the hand having to do all the work.

That's my take on it based on the limited info presented.

You might make a short video of the gun in action to show how the cylinder moves.

cwalter · #4 10-24-2021, 12:15 PM

Side plate has not been off by anyone but S&W. I'll take some pictures of the hand as well as a video of the gun working. I have the side plate off now just to see if anything glaringly obvious would pop out but nothing obvious to my eyes. To this point I believe S&W did a test fire and shipped it back. The gun has never had the side plate of since it was made. Circa 2006 I found the sear surface on the hammer has some of the chrome flaking off so a new hammer may be in order. Should I not worry about the marks on the ratchet. I have a hew smith's and none of them show this characteristic. But only a few smith's isn't a large enough test pool to see what's normal and what's not.

cmj8591 · #5 10-24-2021, 06:33 PM

Is there something under the extractor star that is keeping it from seating all of the way? Also check to see if the ejector rod is bent and/or the center pin binding.

cwalter · #6 10-25-2021, 03:06 AM

Thoroughly cleaned that area and checked for unburnt powder or ash getting underneath the ratchet. Nothing was there. Of course once I try to make a video, the timing behaves visually but I still have the cylinder that feels as though the hand is pushing against the cylinder holding it against the cylinder stop without the trigger being fully depressed. The cylinder locks up like a colt in single action which I haven't had a smith revolver do unless the trigger is pulled and held which pushes the hand up against the ratchet further which inturn puts pressure against the stop if I'm understanding the mechanics of it correctly. Ejection rod and yoke are straight. I'll have pictures of the hand up shortly.

cwalter · #7 10-25-2021, 03:38 AM

Here are some pictures of the hand. Hopefully the pictures are good enough to see some detail of the face that interfaces with the ratchet.

chief38 · #8 11-01-2021, 08:05 AM

New guns are laden with burrs, sharp edges all over, poor fitment from the Factory, etc. Wearing in the parts by shooting hundreds of rounds should smooth it out a bit. Worst case scenario, if it worsens - you have the lifetime warranty, just make sure you keep all the paperwork from the recent visit back to the Factory.

Hondo44 · #9 11-03-2021, 04:16 PM

What do you mean it didn't have the issue before?

Your symptoms are indicative of a hand that's just a slight bit too long, i.e., too tight for the ratchet space. It's pushing the cyl a little too fast for the cyl stop latch to disengage the cyl notch completely first. I would stone the surfaces of the tip of the hand that engage the cyl ratchet teeth: smooth them with a stone and just break the sharp edges, then polish them.

Or take to a revolver smith.

The parts will break in eventually as said above, but every time it's cycled there's strain and wear put on the ratchet teeth, the cyl notches, and the side of the cyl stop.

Good for you for detecting the binding.

Bill Lear · #10 11-06-2021, 03:08 AM

Quote:

Originally Posted by cwalter

Here are some pictures of the hand. Hopefully the pictures are good enough to see some detail of the face that interfaces with the ratchet.

It's the OTHER side we need to see...the side that impinges on the cylinder ratchet to revolve the cylinder counter clockwise.

However, from what I can see, that hand looks pristine.

cwalter · #11 01-02-2022, 11:52 PM

Finally had a moment to look at this gun again with holidays being over. I marked the ratchet with a paint pen on the lands. I dressed the hand very minimally with a very fine stone to help the rubbing concern. While it is better, the concern is still there. I've included pictures of the ratchet so the problem would be clearly visible. No effect was observed on timing. I was dressing the lower portion of the hand as the permanent marker was being rubbing off the bottom of the hand. When I say lower portion I'm referring to side of the hand opposite of what first engages the ratchet. Should I let what's taking place take its course or have it addressed in a more in depth manner? I've also included the wear pattern the hand is producing on the ratchet with a paint pen.

ken158 · #12 01-03-2022, 12:09 AM

I believe it looks pretty good. This is a new revolver that is timed tight and sure beats one that does not carry up properly. Be sure you have at least empties in the cylinder and cock the hammer back regular - not real slow. That is a massive heavy cylinder and the momentum when it rotates. Dry firing and just using the gun will smooth it out.

cwalter · #13 01-03-2022, 01:53 AM

I'll just enjoy it then. I'm nit picking this gun since they didn't make that many of them. Thank you for the feedback. Much appreciated. I've included a photo without the paint so other folks can compare if they run across the same concern.

Hondo44 · #14 01-03-2022, 06:57 PM

Quote:

Originally Posted by cwalter

I marked the ratchet with a paint pen on the lands. I dressed the hand very minimally with a very fine stone to help the rubbing concern. While it is better, the concern is still there. I've included pictures of the ratchet so the problem would be clearly visible. No effect was observed on timing. I was dressing the lower portion of the hand as the permanent marker was being rubbing off the bottom of the hand. When I say lower portion I'm referring to side of the hand opposite of what first engages the ratchet. Should I let what's taking place take its course or have it addressed in a more in depth manner? I've also included the wear pattern the hand is producing on the ratchet with a paint pen.

Just FYI: while you did no harm, the lower portion of the hand that you dressed has no affect on the issue, except your getting hand nose contact on the ratchet that you show in the photos. And that's why you got no change in the binding. It's the opposite edge at the top of the hand that is making the hand bind against the ratchet.

The surface of the ratchet that you painted and that shows the hand contact are really not relevant or important to the binding issue however. It's the upper vertical curved surface of each ratchet that the uppermost top front edge of the hand contacts that can cause binding.

Once the cyl locks any particular chamber into battery, if the hammer still needs to travel slightly further to fully cock by engaging the trigger sear, that's when the binding occurs. Because further travel of the hammer is also advancing the hand further upwards.

Also the top surface of the hand is flat, not curved like the vertical ratchet surface. Look carefully at the top corners of the hand for wear. Those are the contact points to the ratchet vertical surface. Slightly rounding those sharp corners (mostly the right side corner) to match the shape of the ratchet curve will affect the binding and also reduce friction. If then you still feel binding, the hand is just a smidgen too tall.

In a perfect world the cyl stop will lock into the cyl notch at the exact same time the hammer notch and trigger sear engage.

When the lock up of ratchet notch and cyl stop lag behind the hammer - trigger engagement, the timing is behind which is called a "carry up" problem. This is caused by worn ratchet teeth (usually) and/or a worn hand (too short).

When the lock up of ratchet notch with cyl stop precedes the hammer - trigger engagement, you have 'over travel'. That causes binding. This can be caused by worn hammer/trigger engagement, but not on a new gun like yours. Unless the hammer notch/trigger sear are miss-cut which is highly unlikely in a S&W. So that leaves a hand that is slightly too tall. Obviously this is safer than a carry up problem. And perhaps S&W builds this into their guns to allow the parts to wear in a slight bit until the sharp corners are worn off the parts and still not cause a carry up issue after the couple of thousand rounds. Note that the hand is harder steel than the notches because in a 5 shot cyl like yours, the hand gets 5 times the wear of each ratchet notch. But being the softer steel of the two, the ratchets are what will wear in more than the hand. To remain competitive with the price of their guns, extra final fitting of parts is too costly and borders on a custom tuned action.

On my guns I don't mind putting in a little stoning time on those 'sharp edges' to fine tune them right out of the box. You can do nothing and the gun will be fine and get better with use. You sound like me however, but it's your gun and your decision of course.

I hope you find this helpful for explaining what's going on,

Protocall_Design · #15 01-03-2022, 07:10 PM

I have seen a lot of the newer guns with a hand that is too wide rather than too tall. In that case, the hand gets pinched between the frame on the right side and the ratchet on the left side near the end of the cocking cycle.

The fix for that is to put in a slightly narrower hand, or file the left side of the nose thinner with a diamond file. Usually, .001 or .002 is sufficient to correct the problem.