Question about wear pattern on cylinders

[Gary7]

As I've closely examined some of the photos from online auctions of older S&W revolvers I've notice that almost all of them have a peculiar wear pattern on the non-beveled side of the lug recesses on the cylinders. The 28-2 (made in the late 79s) that I just got has it. Is this pretty much just normal wear?

Here are some photos of what I'm talking about:

 

[DON1937]

That looks normal to me for a gun that has fired many rounds of fairly hot 357s. It's caused when the cylinder contacts the cyl. stop. I've seen much worse and the revolver functioned ok.

 

[BruceM]

Possibly the notches are peened from fast double action shooting?



Bruce

 

[brokenprism]

I've always thought that it came from a bolt that drops late; i.e., drops on the edge of the notch where you see the shiny spot, then slips back into the notch. Can't prove it. The previous poster may be onto something too with the comment about fast double-action shooting. I find it easy to believe that when you get the mass of the cylinder in motion, it may slightly overshoot the bolt, which is a lot lighter and perhaps slower.

 

[Alk8944]

Perfectly normal. It happens to all S&W revolvers, no matter if they are shot double action or not. This is the surface which strikes the cylinder stop to stop rotation of the cylinder when the gun is cocked whether by thumb or trigger. The bevel is to allow the cylinder stop to drop into the stop notch, and many times (usually) the cylinder stop hasn't fully engaged the notch before the advancing side of the notch strikes the stop.

No question that the faster the gun is cocked the faster the cylinder turns and the more energy it has when it strikes the cylinder stop. N-frames are particularly susceptible due to the greater rotating mass of the cylinder. This is what is referred to as stop notch peening. The small bright spot in the middle can be caused when the gun is cocked. Depending on stop timing it may be drawn down barely enough to clear the diameter of the cylinder, and when a burr is turned up by the peening the burr can interfere with the stop causing wear to the burr and the small bevel you see. This will be apparent if, when you carefully cock the revolver, you feel a slight "catch" just as the cylinder starts to turn. The burrs can be carefully peened down using a light hammer and smooth faced peening punch.

 

[1 old 0311]

All my Smith's look that way.

 

[rere]

Will the peening punch affect the finish of the cylinder? Of what material is a peening punch made? Is it possible to do this to the cylinder stop notch (window?) I have no intention of doing any of these things. Just curious.

 

[2hawk]

Common questions, it seems...

Many of these questions came up in this thread from a few days ago, in this same section of the forum:

http://smith-wessonforum.com/s-w-revolvers-1961-1980/139918-physics-turn-line.html

I have used a fine diamond file, VERY carefully, to de-burr stop notches. I would not want to peen the burr over into the notch, so my thought is just to eliminate it. Not something you want to overdo, at all.

 

[Alk8944]

Will the peening punch affect the finish of the cylinder? Of what material is a peening punch made? Is it possible to do this to the cylinder stop notch (window?) I have no intention of doing any of these things. Just curious.

A peening punch is made of hardened steel with a slightly domed face well polished. You will be able to see the burr has been peened, but you will need a magnifier to see it if done correctly. The blue will remain well enough intact that no difference wall be seen.

Usually it isn't necessary for the stop window, but can be. This is a different matter because of the thin and unsupported area where it is. The reason it usually won't be necessary is the area of contact between the stop and window is 3-4 times the area being contacted by the stop in the stop notches, so it usually isn't damaged



And for 2hawk,

Done correctly you are not peening the burr into the notch, you are returning metal that has been peened from the side of the notch back to where it came from.

 

[dant]

we always "peen" them, if you file it, the material is GONE, as well as the surface finish...as said above if done 'correctly, it is hardly noticeable. Those pictrues are not that bad, and some touch up would help also,just IN the notch, not on the surface (outside) of the cylinder, as cold blues do NOT match ( blend) well with Smith and Colt finishes, except the Colt 'matte' or beaded can be blended in......also the model 28 in some areas.......just not on the flats (sides) or out in the "open" like on the sides of the barrel......

 

[2hawk]

That's why I love this site!

Thanks for the clarification on peening, and for the filing that I've done-

I guess someone tried to peen the burr on a gun I had, but that just folded it over into the stop notch, where it seemed like it wanted to raise up again. Just an annoyance more than anything else, it was pretty microscopic; but you do notice if your cleaning rag catches on something that shouldn't be there.

Luckily, this was on an s.s. gun, so there's little evidence to see now...