Cylinder replacement?

[Boogsawaste]

I believe 10-7 and later have the gas ring change(hopefully someone can confirm or correct me on this).

I've swapped a couple cylinders myself and they both worked good. Both were done for cosmetic reasons on k frames.

I would also pull your side plate if you're comfortable with that and measure the hand. If it's an oversized it could complicate things and if it binds with the new cylinder a stock size might possibly be needed. Of course the opposite could be true that the new cylinder could require an oversized hand and you have a stock one installed.

 

[calmex]

Just my opinion again, but I think it's a flaw in the steel that got past quality control. I have a Model 49 with what was obviously and air-bubble in the steel on the inside wall of one cylinder. It does not bother anything and I have never felt the need to replace the cylinder -- the brass does not hang up on extraction or anything but it's visually disturbing if you want to lay awake nights and worry about such things. (I wish the World would get back to a point where I could honestly feel that laying awake nights worrying about an air-bubble in one of my Model 49 chambers -- one that doesn't seem to cause any serious side-effects -- wouldn't seem like arrogance.)

In this case, there are side-effects so the cylinder should be replaced. Try and find one that fits -- and yes there are differences with some that prevent them fitting properly so you have to look a bit. In my own case, usually there's several in a box from "cut up" guns and if that one there doesn't fit, this one over here might.

 

[Big Cholla]

Better pictures make me sure that cylinder chamber was subjected to an overload sufficient to make it stretch almost to the fracture point. I can now say with no reservation, that cylinder must be replaced and destroyed. As many have testified; finding a replacement should be no problem and will most likely be a "drop-in" fit.

Obviously, someone was aware of the situation, marked that chamber and then used the gun as a 'five shot'. The problem with that thinking is that if one chamber was damaged, other chambers might have been subjected to the same over load thereby bringing them somewhat closer to failure, but not as obvious to the eye. ............ Destroy that cylinder. They are just too cheap and available to take a chance with this situation ...............

 

[4barrel]

If you get one with the ejector rod make sure it is the same barrel length as yours. 4 or 6 inch is different.

 

[BC38]

Is it possible the gun has been dropped or struck, denting the outside of the cylinder and cracking the inside?

I got the gun at a local auction - it and about 1300 other guns came from one estate. I ended up coming in late and didn't get to preview it, though this damage is so hard to see I doubt I would have noticed it even if I had looked it over beforehand. All that is just to say I have no idea what could have happened to it in the hands of the previous owner and since he's passed away there is no way to ask him either.

HOWEVER, I doubt that the damage happened as you suggest because a) it isn't cracked inside, and b) it isn't bulged inward inside either. The damage on the inside virtually mirrors the damage on the outside. The cylinder wall has a slight bulge-line outwards on the inside and a slight valley-line inwards on the outside. I can't imagine how an impact to the outside could possibly do the type of damage that is inside the cylinder,

 

[BC38]

Just my opinion again, but I think it's a flaw in the steel that got past quality control...
...In this case, there are side-effects so the cylinder should be replaced. Try and find one that fits -- and yes there are differences with some that prevent them fitting properly so you have to look a bit. In my own case, usually there's several in a box from "cut up" guns and if that one there doesn't fit, this one over here might.

It is certainly possible that there could have been a flaw in the steel that contributed to this failure. Not a certainty, but certainly a possibility. I wish you lived in my neck of the woods if you have access to a supply of several cylinders to try...

Better pictures make me sure that cylinder chamber was subjected to an overload sufficient to make it stretch almost to the fracture point. I can now say with no reservation, that cylinder must be replaced and destroyed. As many have testified; finding a replacement should be no problem and will most likely be a "drop-in" fit.

Obviously, someone was aware of the situation, marked that chamber and then used the gun as a 'five shot'. The problem with that thinking is that if one chamber was damaged, other chambers might have been subjected to the same over load thereby bringing them somewhat closer to failure, but not as obvious to the eye. ............ Destroy that cylinder. They are just too cheap and available to take a chance with this situation ...............

I think you and I are on the same page here. Maybe there was a flaw that lead to this particular chamber failing, but it sure looks to me like it is stretched - and stretched just almost to the point of rupture. It is certainly possible that others have been weakened by similar overloads. After discovering this problem I have no intention of shooting it again until I replace the cylinder.

Hopefully I get lucky and the first one is a drop in. If not, trying multiple different cylinders could get pretty spendy.

 

[BC38]

If you get one with the ejector rod make sure it is the same barrel length as yours. 4 or 6 inch is different.

Good point, but if I get one that is different I can just re-use my extractor rod!

 

[BC38]

I believe 10-6 and before have the gas ring like yours (hopefully someone can confirm or correct me on this). If this is correct that's good news because there were so many 10-5's and 10-6's made that finding a cylinder should be very very easy.

So you're saying 15-4 and LATER and 10-6 and EARLIER both use the cylinder-mounted gas ring? That seems really confusing to me. Why would they switch TO the cylinder-mounted gas ring with a new rev of the model 15 and switch AWAY from the cylinder-mounted gas ring with a new rev of the Model 10? That seems bizarre, illogical, and arbitrary to me. Unless they tried it and decided it didn't work well and went back to the other style. Can anyone explain this one to me?

I would also pull your side plate if you're comfortable with that and measure the hand. If it's an oversized it could complicate things and if it binds with the new cylinder a stock size might possibly be needed. Of course the opposite could be true that the new cylinder could require an oversized hand and you have a stock one installed.

Sounds like good advice, but I think I'll try dropping a new cylinder in to start with and see if it works. If there is any binding or "slop", then pulling off the sideplate seems like the next logical thing to do.

 

[Big Cholla]

BC38: When you get your cylinder PM me and I will give you my email address. I will then help 'talk' you thru the swap and checkout "IF" you want the help. If not I understand. Just get Jerry Kuhnhausen's book, "The Smith & Wesson Revolver-A Shop Manual". Used copy's are available thru Amazon. ............

 

[k22fan]

[...] cylinder-mounted gas ring? That seems really confusing to me. [...] Unless they tried it and decided it didn't work well and went back to the other style. Can anyone explain this one to me? [...]

Many sources including the SCSW write that for target sighted K frames with K prefix serial numbers the dash number increased to 4 when the gas ring was moved from the yoke to the cylinder. That's just enough correct information to unintentionally mislead most readers into believing gas rings in the cylinder were new in 1977. S&W installed gas rings in all their revolver cylinders starting before 1900 and continuing through this day with the sole exception being about a year and a half of K frame production. Roughly 1975 S&W quit pressing gas rings into K frame cylinders to save money. They did not change the dash numbers at that time so earlier dash 3 K prefix serial numbered revolvers have a gas ring in their cylinder and later dash 3s have a "gas ring on the yoke."

While other members write replacement cylinders dropped right into their S&Ws neither of the two I purchased did. Some times "fitting" a cylinder involves work in a metal lathe. Since I don't own a lathe, absent a test installation before purchasing a cylinder I'd send the revolver to S&W. Let them paw through their selection of cylinders for one that requires the least work to install.

I agree with you and Big Cholla on the chamber having been distorted by an over load. The first place 6 shot S&W cylinders distort from high pressure is the bottoms of stop notches. That creates dimples in the chamber side walls under the stop notches. I believe I see the dimple in your picture. At about +P pressure .38 special brass will bulge to fill the dimples, not spring back, and make extraction difficult. Using only your other five chambers did you get easy extraction at standard pressure but hard extraction at +P?

I'll add a story purely for your entertainment. An old fellow that I shared the local range with damaged both multiple rifles and multiple revolvers with his reloads. He continued firing a S&W 1917 and a 29-2 after he flattened one of their chamber walls against the bottom of their top straps. He'd open their cylinders to rotate them past the flat spots and align the usable chambers with the barrel.

 

[Boogsawaste]

Sorry BC38. I misread what dash your gun was and thought it was earlier. The 10-7 (standard barrel), and 10-8 (heavy barrel), have come up as gas ring change. So 10-7 and later.

I think this has come up before so if you search something like m10 engineering changes on here it should turn up info. Definitely double check this before you buy one as I'm merely a hobbyist. Hope this helps.

 

[Josh M.]

As you can see, from the outside the cylinder does NOT appear cracked

Yup, thats a crack.

 

[BC38]

I agree with you and Big Cholla on the chamber having been distorted by an over load. The first place 6 shot S&W cylinders distort from high pressure is the bottoms of stop notches. That creates dimples in the chamber side walls under the stop notches. I believe I see the dimple in your picture. At about +P pressure .38 special brass will bulge to fill the dimples, not spring back, and make extraction difficult. Using only your other five chambers did you get easy extraction at standard pressure but hard extraction at +P?

I haven't fired any +P in it - thankfully. All I've shot through it are 158gr LRN target loads that chronoed in the 650-750 fps range. While the cases have all been hard to eject from that cylinder, only one of them actually split.

I'll add a story purely for your entertainment. An old fellow that I shared the local range with damaged both multiple rifles and multiple revolvers with his reloads. He continued firing a S&W 1917 and a 29-2 after he flattened one of their chamber walls against the bottom of their top straps. He'd open their cylinders to rotate them past the flat spots and align the usable chambers with the barrel.

Pretty crazy. Definitely not for me! Now that I am aware of the damage, I won't shoot any rounds in any of the chambers of that cylinder. This one is a paperweight until I replace the cylinder.

You only get one pair of hands, eyes, etc...

 

[BC38]

Yup, thats a crack.

NOPE, it is NOT a crack - trust me. I've removed it from the gun and inspected it very closely IN PERSON (as opposed to looking at grainy low-res pictures on the internet).

There is a scratch mark on the outside - obviously put there by the previous owner to mark the bad chamber - but it is definitely NOT cracked.

Stretched and damaged, yes, but cracked? No. Sorry, but you are mistaken.

 

[BC38]

Got the replacement cylinder the other day and got around to fitting it today. I ran into one issue. The center pin from my ejector rod won't work with the extractor on the new cylinder because the "shoulder" on the center pin that the spring pushes against is about 1/8" too close to the end of the pin. It wont go into the barrel of the extractor far enough for the end of the pin to protrude from the center of the extractor.

So, next I tried to re-use my extractor and discovered that when I insert it into the cylinder, the teeny tiny little pins in the cylinder don't quite line up with the holes in the extractor star, so it won't drop all the way in.

I temporarily removed the pins and reassembled everything with my extractor, and everything looks very good. The timing, lockup, etc. all look good to me. I think I may need to get a new center pin that fits inside the ejector rod - one that has the shoulder set about 1/8" farther from the end (dimension A in the attached photo).

 

[Big Cholla]

BC38; Give me the measurement to the shoulder and the over-all measurement of the pin. I probably have one that you can have. PM me with the measurements. .............

 

[BC38]

BC38; Give me the measurement to the shoulder and the over-all measurement of the pin. I probably have one that you can have. PM me with the measurements. .............

I sent you the measurements - thanks man!

A big thanks to Yorkie Man for donating the cylinder also.

We'll have this old girl firing on all 6 again in no time.

The folks on this site are the absolute best I've seen in any forum anywhere!

 

[BC38]

Well, everything is back together again and looks to be 100% Of course I won't know for certain until I take her to the range, but it's looking very good.

I got the center pin from Big Cholla in the mail today and put everything together - only to discover that the spring that keeps the center pin extended was too long. With the shoulder set back 1/8" further on the new pin, the wraps of the (longer) old spring were fully compressed and pressing against each other so the pin couldn't retract into the extractor star.

Out came the wire cutters and a snip to take just under 1/4" off the uncompressed spring and VOILA' it now retracts far enough but still latches securely.

So everything is back together and functioning smoothly. Lockup and timing look good, no more end shake or looseness than it had before, forcing cone to cylinder gap looks good. I think she's ready to go again.

Once again, thanks for all the help and the parts donations guys. You really are a great bunch!

 

[BC38]

Well, I took it out today and put a couple of dozen rounds through it. Shot perfectly, no lead shaving, empties ejected perfectly. It's back to 100% thanks to the help from all you fine folks! Thanks again, guys...

 

[calmex]

Impossible problems, questions and technical issues are resolved almost daily on this forum with such regularity that many of us almost take for granted that "it's no big deal" but when it's your gun that gets fixed miraculously when it otherwise probably wouldn't have been one appreciates it more. I've had quite a few "miracle saves" thanks to the members of this forum as well and can fully appreciate how you must feel.