Hello guys,

I am fairly new to revolvers. Bought S&W 627 8 shots scandium cylinder about a year ago and shot about 1000 rounds / dry fired probably 3000 times.

There is now noticable peening on the cylinder notches as you can see on the pics below.

I have read quite a bit since about this, I understand this probably due to some of the revolver components being not 100% perfectly fit and that at some point the wear should stop.

My intutions says however that this is a bad start and that I am eventually have to go through the hassle of having my revolver repaired.

I live in France, basically a third world country when it comes to acquiring and maintaining weapons. Ordering a new cylinder can take up to year....!

Any kind advice on the current state of the cylinder and what I may do to stop the erosion of the notches would be much appreciated, I can post more pics if needed.

Regards,

Wissam

20171205 201521 — imgbb.com

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Edit, sorry couldn'nt figure out how to display the pictures here, added links instead

I'm not seeing the pictures

Sorry, but your pictures are not showing for me.

EDIT: Embedded your pics for you in post #6 below.

Welcome to the forums.

I don't see any attached or linked photos

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NEVER GIVE UP YOUR GUN

Sorry for this, just added links instead for now

I figured it out. You didn't use the embed codes at the bottom of the pics. I went ahead and copied them in this post for you.

Jim

I wish I could give you a hand with your problem, but I have zero experience with titanium cylinders so I really can't even try to hazard a guess on what is happening. But you definitely have some peening going on.

Thank you Jim.

Any advice on how dealing with this issue ?

I see nothing unusual but normal use

From your experience penning should stop at some point ?

I think a little bit of smoothing the edges and taking a bit off the thickness of the cylinder stop with a fine arkansas stone will solve the issue.

The sideplate will need to be removed and the interior disassembled to get at the cylinder stop.

There are you tube videos if you don't have S&W revolver disassembly experience and knowledge.

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NEVER GIVE UP YOUR GUN

Good day, If you can call S&W and ask if the gun can be sent for inspection, that should be covered under warranty. International number 1-413-781-8300

Was this (3000X) RAPID dry, & (1000X) RAPID live fire? If so, as much as I hate to say it, it doesn't look "too bad" - for 4000X. Especially considering a titanium cylinder.

Understand you find it irritating, as it would bother me too.

Others may disagree, but I personally think that "high speed" cylinder revolution - only being stopped by the small (but hard) cylinder bolt slamming into the relatively small notches (even in a steel cylinder), tends to promote peening.

I tend to handle the bulk of my dry, & live fire (for training purposes at least), w/ slow / deliberate action - for this very reason.

Goes without saying that, although replacement parts are "theoretically" available from S&W, the technical expertise required to fit a new cylinder - may not be readily available near your location.

I wonder if S&W would handle this problem, as a warranty?

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Regards - GCF

There is definitely peening of the cylinder notches, on the edge that takes the pressure when the cylinder comes to a stop.

I would say this is probably from cycling the action TOO fast with an unfluted cylinder, however this would be a steel cylinder, and yours is whatever, so not sure if same weight.

Due to the lockup design of S&Ws, one cause of this would be cocking the hammer or pulling the trigger like a madman, making the cylinder rotate very fast then coming to a complete stop against the bolt (stop). Unless something about these particular materials makes them weaker, I don't know because modern S&Ws don't interest me to study them enough.

Also due to the design of S&Ws, with their "auto bore alignment", I don't think any "play" that this peening may cause would make it shoot bad, as the cylinder will still self align when fired.

Now if it was on a Colt V spring action, the "play" that peening creates would affect chamber to bore alignment, and eventually repairs would need made, which would be a new cylinder.

Good thing is your gun should have warranty and be taken care of if needed.

Side note, sometimes "peening" or "dragging" will occur in that same location, but it's not from cylinder travel, but rather the bolt (stop) not fully retracting from the notch before cylinder rotation begins. However, that doesn't appear to be what's happening here.

Well yes, there no staging of the trigger, mostly rapid double action pulls.

I don't mind pulling the trigger slower if that can help stop the peening. I heard that the peening will eventully stop, that the cylinder notches are currently being in an "ajustment" phase...does that make sense ?

I don't think the 627 has a titanium cylinder.

Is a scandium cylinder

They make scandium frames. They make titanium cylinders. They don't make scandium alloy cylinders.

I stand corrected.

Here's the model I have

PERFORMANCE CENTER(R) Model 627 | Smith & Wesson

Thank you all for your helpful responses. I've got now much better insight on how I should deal with this.

The ramps leading into the notches are cut too shallow. What we are looking at is more tearing off material than peening. When the cylinder is cycled quickly (especially a stainless non fluted one) the rotational inertia and speed is enough that the cylinder stop doesn't have time to drop into the notch and is just catching the corner of the other side. Also, the ramps are off center to the cylinder stop which is causing the stop to hardly go down at all as it comes to the notch. The line on the cylinder needs to be centered in the ramp.

The real solution for this problem is to recut the ramps to the correct angle and depth. This is easily done on a milling machine by a qualified machinist. It can also be done by careful hand filing with a round file. A chainsaw sharpening file would work. I had to do this on one of my 627s that had the exact same problem. It has now worked perfect for thousands of rounds.

Peening never goes away. It is always an issue when shooting fast or just a lot of rounds. The fix for peening is to use a flat ended punch and move the material back where it came from. Do not file it off. I don't like non fluted cylinders because of the problems caused by the heavy weight. Your gun will last longer if you slow down the speed of the cylinder.

Yes, I agree with Toolguy. Look at where the ramp meets the actual notch. Shouldn't be that much of a ledge and the fact that the "drag" line is forward of the center of the ramp. That part of it might be the shape of the bolt itself.

What you are seeing is normal ....do as StakeOut (post #11) recommends. A lot of double action work , especially dry firing , will do this. Nothing to get alarmed about, it's just normal wear that happens from 4000 DA cycles. Smooth the edges with a stone.
Less rapid dry firing will extend the life of any gun but like a car ....if you drive it , it's going to get a little wear and tear on it .
Just remove and smooth up the notch edges and carry on.
Gary

This is not normal. This situation causes the cylinder to skip a chamber and come to rest in between or go to the next one.

Welcome to the Neighborhood!

I will try to find a competent gunsmith, perhaps next door in Switzerland.

smoothing the cylinder stop edges, if that is a viable solution, is probably the only thing I can do on my level.

See below a few pics of how the cylinder stop looks like,



upload pic

You can notice where the black coating (the opposite side where the peening is occuring) is going away, seems like only the third of it is connecting. I wonder if the stop is even, or if it is not sitting a in a slightly oblique/inclined position.

Should I file the stops edges to make them less "edgy" ? Acquiring this part is easy, messing one up is no big deal.

How about filing the top of it, perhaps the changing the shape of it would have it hit nearer to the ramps center ?

Thanks for reminding us, Bill! Welcome to the asylum, wboustany!
Cylinder stop is fine. Don't mess with it.

Excellent first post Toolguy, and I'm glad you spoke up again so this is clear to everyone. I got to learn something new today.

It seems you nailed it, and you can tell how long you've been tinkering with these.

My 629-2E 3" from 1989 has practically the same lead and notch system as on this new one, the updated long notches of the endurance package, but the leads are just as shallow after another review due to this thread.

I have some notch peening. At first, I thought it was just due to the steel unfluted cylinder, but now after checking, it is only at the top, and due to the shallow leads contributing, along with the heavy unfluted cylinder of course.

My bolt (stop) "path" is mostly centered until it gets to the lead, then it is slightly off centered towards the front while in the lead, but not as far off as the OP's example. I don't think a little bit of off center-ness matters with the bolt head, but I may be wrong. I think it's more the other factors all contributing to the issue.

Would have been nice to know this when Frank Glenn had it. No more fast DA or cocking I suppose.

Yes, but that's it the first time I've seen stop-notch guides cut north of max diameter such that they are egg shaped. I strongly doubt there is any ill effect, but is interesting to me since I've never seen it before.

To iPac - Not really my first post, but no big deal. If you want to send me your cylinder and pay postage both ways, I will fix it as a Pro Bono Karma. I would make the offer to the OP, but he's in France and shipping that back and forth isn't happening, thanks to international laws.

And the specs of the revolver linked in one of the posts specify stainless steel frame and cylinder.

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Pisgah

Suggest you don't file on the cylinder bolt (stop), as it looks OK.

Go back & re-read Tool Guy's post #20. Pretty sure he is on to something.

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Regards - GCF

Yes, but that's it the first time I've seen stop-notch guides cut north of max diameter such that they are egg shaped. I strongly doubt there is any ill effect, but is interesting to me since I've never seen it before.

Edit,
And off center...If I had free time I would send the pics to S&W just to get their opinion. The may replace the cylinder...

"You can notice where the black coating (the opposite side where the peening is occuring) is going away, seems like only the third of it is connecting. I wonder if the stop is even, or if it is not sitting a in a slightly oblique/inclined position."


Cylinder stops are not flat on the top of the ball, but are slightly higher on the "frame" side, or the left side when looking from back to front. Wear is more prominent at the crown of the ball at this point. (high side)

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Ret. LE, FA Instr, S&W Armorer

I looked at a few of my S&W revolvers and didn't see any egg shaped notches. Looks to me like the cutting tool was set to cutt too shallow and left a double tapered scallop instead of a continuously deepening ramp leading to the bolt notch. This would have the effect of pushing the bolt back down as it followed the notch, depending on how close the bolt was timed. There's supposed to be just a small step to let the bolt rise a short distance into locking engagement. The way these notches are cut the bolt will be pushed back down out of engagement before springing back up to engage. If the cylinder is spun fast enough the bolt will smack into the far side of the notch instead of the bottom, hastening the peening effect seen in the photos. The other bad thing might be simple mis-alignment of the stop notches. When the piece is fired those mis-aligned notches and the bolt get forcibly lined up as the bullet engages the throat, also peening the notch side as shown. If this piece were mine I would either sell or have S&W take a look.

I agree with toolguy and steelslayer. From your pictures I also see a slight ridge at the end of the bevel (I've marked this point A in your picture). this bevel could make the lockup bolt "hop" slightly as it passes over. The bolt would not fall directly into the notch, but would contact point B on its high point, causing the peening, then fall into the notch.
As a S&W armorer, I've not seen this situation before, but with a small round file it should be easy to correct.
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I don't have Alzheimer's- My wife had me tested.

Attached Images

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Thank you guys for taking time to advise me on this,
I am have a much clearer picture of what's going on now .

I have contacted Smith & Wesson's rep office in France to see if the terms of the guarantee would take this in charge.

If not, I will most have the ramp filed the way you advise.

Do you think that a stronger stop spring (wolf springs sell one) would reduce the tearing ?

On this one, I would do anything that might help. I say yes, get the spring. It will help a little bit, but not a substitute for making the ramps right.

The more I look at the pictures the more I see. I believe your cylinder was mis machined. The ramps are not centered to the notches and the should be. Look at the turn line. It is centered to the notch. There is much more notch in front of the ramp than behind. Should be even. I would be asking for another cylinder. I guess, the ramps could also be filed forward and centered when adding depth. You shouldn't need a stronger spring. If the bolt is bouncing like Tex1001 thinks, it might make it worse by slamming the leading bolt down even harder on the far edge of the notch.

This gun needs to go back to a repair center, Its not right, should be and needs to be and another thing is the cylinder has a treatment on its exterior and filing will remove that. I doubt that is a huge deal function wise.

This is a photo of my 642. Over a thousand rounds shot, and probably a thousand dry fires. This cylinder is aligned pretty good evidence by thin, nearly centered turn line, and virtually no peening. Don't know if this is the reason for lack of peening

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John

I know it's not your first post, I was referring to the first one of this thread. I have observed how much experience you have working on these guns, so I pay attention when your types speak. As I'm still learning the intricacies of S&W revolver smithing, I started with Colt V springs.

I very much appreciate the offer. Actually, if I had a proper round file, I imagine I could do it myself by hand as mentioned. I will keep you in mind though, but will have to pull the 629 and give it another exam. Either way, I may contact you for more detailed specs if I decide to pursue anything.

Mine is not near as bad as the OPs, mainly because it hasn't been shot fast DA that much. Slowing down on the trigger pull and hammer cocking will do wonders on their own to stop this phenomena.

As to the cylinder leads and notches, all those who think the "leads" are milled off center to the notch are incorrect. Once the endurance package updated the stop notches to the long variety, the leads are off center and that is by design.

Now my question for Toolguy, and any other armorer/smith, the shallow lead ins, would you consider this a "design flaw" on S&W's part???

Because mine was made in '89 and the OP's is a new one, so this means they have probably been machining those shallow leads for quite a while. Actually, this might be why I keep seeing "notch peening" on certain examples that are shared here, but I keep my mouth shut usually as to not rain on parades, but I have noticed it is fairly common. However, I have not paid attention to the specific models when I observe this.

Here is a pic of mine:



Please read my comment above.

If the cylinder lead was centered to the notch, then the bolt/stop would almost be riding on the bare cylinder or at least the extreme rear edge of the lead, because the bolt is stationary in the frame. The cylinder notches and leads need to be cut in alignment with the bolt/stop, not the other way around. Just think about it for a second.

This is by design with the endurance update.

Actually, your turn line is slightly off center (barely), but I'm almost sure that has nothing really to do with lockup unless it's completely fudged up. As Toolguy already informed the OP his bolt/stop is OK, and it isn't perfectly centered.

I've seen tons of revolvers with off center turn lines, and while probably not perfect per factory spec (like Colts), they still function just fine with no issues of bolt/notch lockup. All it takes is a steady hand and file to re-contour the head if desired, and possible, but you need to know how to do it properly.

My '72 Python had this issue, and I recontoured the bolt head. Now I have 2 turn lines within the lead that are side by side. Probably didn't need to do it, but I'm anal with perfection, so my guns get corrected to factory spec.

Also, a 642 isn't really a good gun to bring in as an example. That's a J frame and these are unfluted N frames.

I'm sure there are quite a few guns out there just like the OP's and mine, if the milling has been done the same for all that time. The difference between knowing this and not knowing it, would be how much "use and abuse" does average Joe inflict upon his revolvers? In most cases, folks probably don't shoot or use them enough to make the problem surface. This is how it is with many many issues that just aren't noticeable to anyone except experienced tinkerers or those who actually "use" their guns enough to make those issues arise. Most of it ends up being factory too.

All I know is the bolt is not going into the center or riding in the center of the lead in. The big thing about that is it also means it is not riding in the deepest part of the ramp (lead in) this means it is higher when it goes over the edge to drop into the actual notch. Therefor less apt to hit the bottom of notch before it is slammed into to stop side, NOT RIGHT. True the cylinder or bolt can not be moved to center it, but open your eyes, if the lead in was about .03 forward it would be centered in the notch on that gun and the bolt would ride into and down it correctly. Cylinder machined wrong.

I can only imagine the ugly mess that I would make out of a cylinder if I ground on the ramps with a round file. It would take an exceptional hand to make five or six uniform cuts.

This has been an exceptionally educating thread. Dabbling almost exclusively in old S&W's, I have never noticed this anomaly, nor appreciated the exquisitely accurate machining that went into old cylinders in the pre-CNC era. Shame on the newbies at S&W for letting modern machining and inspection equipment let one like this slip out the door.

To iPac - The ramps on yours could be a tiny bit deeper, but they are pretty normal. I wouldn't do anything to them. You can center up the turn line by reshaping the ball on the cylinder stop so the highest point is in the middle of the ramp. That would take about 5 minutes with a small flat file. This will allow the cyl. stop to sit a little deeper on the ramp and be slightly more engaged when it hits the far side.

The ramps are not in the middle of the notch on a gun with the endurance package, as you say, because the notch has been extended forward. The stop should still be centered in the ramp, though. The endurance package is a very well thought out and carefully engineered improvement for heavy recoil calibers. Kudos to S&W on that one.

What we are seeing on your gun is just the normal tiny imperfections that come with a mass produced anything that is a fairly precision piece of equipment. On nearly any gun there are minor tweaks one can do to make it more nearly perfect.

As for the peening, any revolver that gets used a lot will have that to some degree. The heavier the cylinder and/or the faster it rotates, the more peening will occur. In your case, I would do a minor adjustment to the cyl. stop and move the material back where it came from. On the straight side, use a flat bottom punch and on the ramp side, use the side of a 5/16" steel rod, preferably hardened. You will find that this also tightens the lockup just a wee bit as well.

Revolver smithing is often the art of adjusting that which is non adjustable. One example is fixing the peening issue. Another is moving the cyl. stop rearward if you need just a bit more engagement with the trigger to advance the unlock timing. You can do this by lengthening the slot that the pivot pin is in with a rat tail needle file. A few thousandths is usually all that's needed.

I understand what you're saying, and not trying to argue. This is for the benefit of all.

I completely understand bolt/stop head contour. I understand under perfect conditions the riding part of the bolt/stop SHOULD be centered to the leads and notches, but this isn't always the case.

What I'm saying is that minor issue maybe contributes about 5% to the issue at hand. It's mainly everything else causing the "peening".

If being slightly off centered truly causes problems, it's probably more common in guns such as ours with the large N frame unfluted cylinders. All others seem to be fine despite it.

Keep an eye on guns being shown, and pay attention to the drag lines. You will see many that are not riding centered. Again, I'm NOT saying this is normal or factory correct, I'm just saying in most cases it will have no ill effect. That's an opinion.

Toolguy - my notches may appear slightly deeper than the OP's gun, but I don't think it's much deeper if so. My gun hasn't been fired rapid DA or fast hammer cocking at all by me, so what "peening" you see is from very limited use, probably by the original owner I bought it from.

I will attend to it in the future though.

"Now my question for Toolguy, and any other armorer/smith, the shallow lead ins, would you consider this a "design flaw" on S&W's part??? Because mine was made in '89 and the OP's is a new one, so this means they have probably been machining those shallow leads for quite a while. Actually, this might be why I keep seeing "notch peening" on certain examples that are shared here, but I keep my mouth shut usually as to not rain on parades, but I have noticed it is fairly common."


Some addn info based on the appearance of the OP opening photos......To begin, let me say I'm not a machinist. I do have a fair amount of revolver experience going back to the mid-70's.

The "lead in" issue per se is not a S&W "design flaw" as has been suggested, but the lead-in cuts on the cylinder shown by the OP do appear to be defective. Looks to me like the cutting tool was positioned in the wrong place, which resulted in what could be described as a "lead-out"....that is the oval shaped cut does not stop at the edge of the slot at the cuts lowest point as it should, but actually comes back up. As others have said, as a result, the stop actually is forced back out of the cylinder as it prepares to drop into the slot. I'm not referring to "centering" here, in terms of the relationship of the cuts to the length of the slot, but the shape or "mis-shape" of the lead in cuts themselves.

Making things even worse is what appears to be a very definitive burr at the entry edge, as someone suggested in an earlier post. Such a burr can cause the stop to miss (jump) the slot completely. I've never seen a lead-in cut on a cylinder that looked like the one in the OP's gun.

Another component in the peening issue that I don't believe has been mentioned, is the factor of the weight of the unfluted cylinders. Obviously, the unfluted cylinders are heavier than the fluted ones. The extra weight only makes the potential for peening worse. In my experience, this propensity for peening is frequently exhibited by revolvers with heavier cylinders, like the model 27, the model 17, and the L-frame variants, for instance.

I would suggest contacting S&W and submitting some of the photographs, asking them for an opinion on the possible defect.

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Ret. LE, FA Instr, S&W Armorer

I think this is the key issue here. Looks like the ramps were cut off center, on the OP's revolver.

Just looked at three of mine: a M640-1, a M65-3, & a M686 no dash. Bolt turn lines are PERFECTLY centered on the ramps. For the record, no peening either...

My suggestion to the OP, is to ABSOLUTELY NOT try to resolve the situation w/ a file, but to pursue a warranty resolution through S&W. What ever it takes. Be a good idea, to point out the off center ramps (send pictures), when speaking w/ S&W customer service - about the issue. Bet they replace the cylinder.

Pretty sure any filing (by the OP, or a 3rd party gunsmith), will void the warranty.

Must say, I've found this to be one of the most informational threads - posted here in a long time. Gotta' love this place!

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Regards - GCF

I am no expert but I know that if the barrel cylinder alignment is off a little it will result in peening caused by the rebound action of the bullet hitting one of the sides of the of the forcing cone more than the other. Misalignment can also cause dangerous cartridge pressures and degredation of accuracy. It's always good to have range rods/plug gauges to check the alignment. They are available through Brownells and are relatively inexpensive.

I would slightly chamfer the leading edge corner on the stop.

There will always be peening to some degree on a revolver cylinder. That is normal wear & tear. What's more important is ensuring the timing and amount of cylinder play is within spec.

I am quite positive based on the photo that your pistol is fine. Unless the good folks commenting here are certified S&W armorers, and even if they were it's impossible to diagnosis a firearm over the internet. I wouldn't take their advice too seriously. If you really want piece of mind, I suggest calling S&W customer service & talk to them. If they feel that they would like to check it out then they will send you free of charge a FED EX shipping label. Either via email or they'll mail it to you USPS.