Revolver Timing....

[davidk29]

Hi,

I hoping one of you guys/gals can help me with a problem I'm having with my model 28 Highway Patrolman.

For many years, I've only fired the weapon in "single-action". Everything worked fine and I saw no problems either in firing or cleaning. Then, I decided to give "double-action" a try.

That day, I put 100+ rounds thru her and later, while cleaning, I noticed a problem. One edge of each of the cylinder timing notches looked as though it had been peened to one side. The metal was noticeably pushed up. The gunsmith I took it to managed to push the metal back into place, but he couldn't give me an explanation of what was going on.

It looked like the cylinder had been forcefully rotated while the bolt was still in the notch. I decided to use the knowledge I learned to do some troubleshooting.

I checked the barrel/cylinder alignment and it was okay. I then replaced the bolt and did some tuning to smooth things out. It didn't fix the problem. I also checked the ratchet. I plan on replacing the hand as a last resort. By the way, I am a novice gunsmith.

I heard that the quality of the model 28 was not as good as the quality of the model 27. If that's the case, could be metal of the cylinder be softer than it should be?

It's a model 28-2. Looking at the back of the revolver, the damage occurs on the right edge of each notch.

Any ideas would be helpful.

Thanks,
David Kraykovic.

 

[bmcgilvray]

I have no way of knowing but am unconvinced that the Model 28 is made of lesser quality steels than the Model 27. Any differences are surface cosmetics.

The N-Frame .357 cylinder is a fairly hefty chunk and some have said it is more prone to such peening as the smaller sized frames' cylinders. I've shot some of my N-Frame guns double-action a good bit and haven't noticed.

What I have noticed is that an N-Frame fired double-action is a fine-shooting revolver and perhaps the best revolver for such work.

 

[sixpointfive]

Please take a picture and post it, these guys really helped me out with my revolver last week.

 

[lebomm]

It sounds to me like the damage occurs when, in DA, the cyl. stop drops while the cyl. is still in enthusiastic motion to bring the next chamber into battery. Then, as the notch comes into alignment, the bolt (cyl. stop) drops the rest of the way into the notch, bringing the cyl. to an abrupt halt. Several of my revolvers have this kind of burr & it's never been a problem other than cosmetic.

Larry

 

[davidk29]

Larry,

I agree with your explanation about the cylinder/bolt problem of my 28, it sounds really logical.
You said that some of your revolvers have this burr, I assume it isn't a burr that continues to grow with time. The first time I noticed it, I panicked and stopped using the revolver. So, if I would have ignored it and kept shooting, the burr wouldn't have gotten any worse?

Thanks for the info,
David K.

 

[chief38]

davidk29:

As far as the quality of your M28 -2 being of less quality (metallurgy) goes, have NO CONCERNS! The M27 & M28 started off as identical guns made from the same steel and on the same forging hammers. The only difference in the two guns is their finish, and level of detailed work (checkering, polishing, etc).

As for your notch burrs........

Here are a few checks you can perform yourself (make sure gun is unloaded of course).

1) pull trigger slowly and see if the cylinder locks up with the cylinder stop fully engaged BEFORE the hammer falls.

2) Just as the hammer falls, see if the hand is trying to advance the cylinder past where the cylinder aligns perfectly with the barrel.

3) Check to see if your cylinder stop has any burrs on it or is deformed in any way. Make sure it is not higher on one side. Also make sure it is not undersized and leaning into the notch.

4) See if the window cut out that the cylinder stop pops up through is cut true and parallel to the frame.

These are just some of the quick check items I can suggest you look at prior to bringing the gun in anywhere without actually seeing it.

Chief38

 

[davidk29]

Chief38,

I performed all but one of the checks you suggested and all seemed to work properly. I have MS so pulling the trigger "slowly" was a real challenge, I finally had to loosed the mainspring strain screw to lighten the pull a bit.
I didn't perform #2 because I don't know how to do it. Can you give me a hint on how to do it? I would appreciate it.

Thanks,
David K.

 

[chief38]

davidk29

Pull the trigger slowly and put your thumb in front of the hammer so you catch it before it goes down. When it breaks, let the hammer go down slowly and when it's down all the way continue pulling the trigger back 'till it stops. When you do this, see if the cylinder continues to rotate beyond where the charge hole aligns with the barrel. If it does, the hand might be pushing the ratchets too far and causing a burr to form when the gun is fired.

Chief38

 

[davidk29]

Chief38,

Hey, thanks for the guidance in helping me check out my model 28. I'll let you know what I find out.

Thanks,
David K.

 

[sixpointfive]

Burrs

Did the burs look like these?

 

[davidk29]

sixpointfive,

Yes, those burrs are similar to the one I've noticed on the cylinder indexing notches, but I've never had burrs in that particular area of the cylinder. What condition caused the burrs illustrated in your photo? It looks to me as if the hand was continuing to try to rotate the cylinder after it's locked in place by the cylinder stop.

Thanks,
David K.

 

[davidk29]

Chief38,

I tried your suggestion about verifying that the hand is not continuing to attempt to rotate the cylinder. I found that after the hammer falls, the trigger cannot be pulled any rearward anymore. With the hammer down and the trigger all the way back, the revolver is locked up solid. You can, however, rotate the cylinder a infinitesimal amount by hand. Then, when I release the trigger, the amount I can manually move the cylinder gets a little greater. It sounds like the hand is helping to lock the cylinder in place, but it's not continuing to push it.

What do you think?
David K.

 

[july1952]

The Model 28 is every bit as strong as the Model 27. The only difference is the extra finishing on the 27 to make it prettier but not tougher.

On your other problem, have you tried replacing the cylinder stop spring? I had a similar problem a number of years ago, sent it in to S&W for repair and the new spring fixed it. The nice thing about S&W repair is they test fire your gun and give it a good going over while they have it. A good thing they did, mine had a cracked forcing cone, requiring the barrel to be turned. They did a fantastic job and it works just like new again.

Good luck and I hope you find a solution to your problem soon.

 

[davidk29]

Unfluted686,

I replaced both the cylinder stop and associated spring when I first noticed this problem, and I recently successfully (I think) performed the suggestions from Chief38. What's maddening is that my 28 appears to pass all of the checks. The two local gunsmiths I visited could find no problems whatsoever.

As far sending it back to S&W, I'm apprehensive because I don't trust the shipping service. In addition, when I sent my 29 to S&W, they replaced the cylinder and the trigger stud. The first time I fired it, the rebound slide spring somehow came out of the rebound slide. At the time, I didn't know enough about the inner workings of a Smith revolver to realize what had happened so I sent it back. They replaced the spring and sent me the old one.

I'm between a rock and a hard place.

Would the hand have anything to do with the problem? I'm looking at things that I can replace.

Thanks,
David K.

 

[chief38]

davidk29

It might be helpful to see a photo of the problem. Post a few if you are able.

The only other thing I can think of "blindly" is that the ratchets were never fit properly to begin with, and so the burrs have formed as a result of being sort of being "force fit" if you will. Yes the hand could be the cause but without seeing it it's hard to make that call definitively. I have seen guns that were fit poorly and over time tend to fit themselves by abnormally wearing at one point or another. I've seen similar conditions exist on motorcycles, cars and other mechanical devises as well.

Here's the important question....... does the gun function properly, reliably and flawlessly? If the answer is yes, then I would say leave well enough alone and keep an eye on the ratchets to make sure the burr does not "grow". If it does change then I would say send the gun back to the Factory even though you have had a bad experience in the past.

Chief38

 

[july1952]

David,
Call S&W at 1-800-331-0852 and ask to speak with Gene Sypek. He is one the master gunsmiths on revolvers. He's a great guy to talk to and should be able to help you. He's worked on several of my Smiths over the years and I would highly recommend him.

Just in case you do send it in, which I would highly recommend, S&W shuts down the entire month of August for everyone to take vacation.

 

[scooter123]

David, I'm going to ask a question that nobody else has thought to ask. How rapidly are you pulling the trigger? Yes there is a potential that how rapidly you pull the trigger factors into what you are seeing. Because the faster you pull the trigger the faster your cylinder will be moving when the cylinder stop drops into the indexing notch. A very simple solution for your problem may be as simple as pulling the trigger just a bit slower, say about 30%. if you are familiar with the equation for Kinetic Energy you'll see that a 30% reduction in the speed the cylinder is rotating will cause a 50% reduction in the Kinetic Energy of the cylinder when it contacts the cylinder stop.

Now for how to determine if you are driving your cylinder "too fast". The best way to do that will require the use of a shot timer. If your split time in double action is greater than about 0.35 seconds it's unlikely that you'll beat up the cylinder stop notches at an excessive rate. Get below that 0.35 second split time and you'll want to plan on purchasing some spare cylinders. BTW, I expect that Jerry Miculek probably replaces his cylinders at a monthly rate, because to get down to a 0.125 second split requires driving the cylinder at a rather extreme rate of rotation.

BTW, depending on distance and how current my practice is, my split times with my 625 ranges between 0.35 second and 0.65 seconds and with over 1500 rounds downrange I cannot see any hint of the cylinder stop notches peening. Thus my recomendation to keep your split times to 0.35 second or greater.

 

[davidk29]

Scooter123,

I think you might have hit the nail on the head! I have literally tried all of the checks that can be performed to verify the timing and accordingly, my revolver is timed properly. I could start replacing things on a whim just like I did with my '76 pinto, but other that giving me experience, I don't think it'll make any difference.

I have to admit that I use the revolver as therapy for my MS so coordination and speed are factors. Since I treated my model 60 in an identical fashion and no peening was noted, I blamed it on my 28, but then again, a 5-shot cylinder loaded with light-loaded .38 specials isn't as large a mass as my 28's cylinder with 6-rounds of factory .38 special.

From now on, I'm going to downshift my rate of fire.

Do you know where I could find an explanation of how the cylinder and hand work in conjunction with each other? A drawing would be nice.

Thanks lots,
David K.

 

[davidk29]

Thanks for the advice about timing...

I wanted to thank you for all the help you've given me about timing and my model 28.

David K.

 

[Nightowl]

I have a 627 that developed burrs on the side of the stop notches. I peened them down a couple of times and they finally stopped doing it. Just broke in I guess. I did not run it fast, either, as I work at prescision shooting double action, rather than fast shooting. I do believe faster shooting in double action would have made it worse. Frankly, I would not worry about it unless it interfered with the smoothness of the action, but I would keep an eye on it.