Chamber expansion in a Smith & Wesson

[spm]

I have a Smith and Wesson model 19-5, 2.5" bbl. chambered in .357 Mag. When I shoot magnums, +P .38s, or even semi-hot standard .38 loads, the empty shells won't extract. I was told I had "Chamber expansion" and the cylinder needed to be replaced. Since we don't have a gunsmith in my town, I thought I'd ask the THR forum; has anyone heard of this, and is replacing the cylinder my only option?

Thanks.

"We deal in lead, friend."

 

[clutch]

Have you tried cleaning the cylinders really good with a brass brush?

Clutch

 

[1911Tuner]

Yep. I replaced the cylinder on a Model 19 for that very thing just last year.

K-Frame .357 Magnum revolvers are marginal when it comes to full-power .357 ammo.

When the Model 19 was developed at the behest of Bill Jordan, the advice from Jordan and Smith & Wesson was:

".38s for practice and .357s for business."

It makes just as much sense today as it did then.

 

[MrBorland]

I was told I had "Chamber expansion" and the cylinder needed to be replaced.

When the Model 19 was developed at the behest of Bill Jordan, the advice from Jordan and Smith & Wesson was:

".38s for practice and .357s for business."

It makes just as much sense today as it did then.

Eh...not to be dense, but I'm not getting it. AFAIK, the admonition to shoot .357s "for business" only was/is based on the frame & forcing cone, no?

Chambers "expand"? I'm no gunsmith, but I've not heard that one before. Brass expands against the chamber, sure, and I suppose the higher pressures of .357mag might mash the brass against the chambers tighter, making extraction harder.

AFAIK, the ejector rod on a 3" gun is the minimum needed to fully eject rounds. My suspicion is that of Clutch - the chambers just need a cleaning, polishing or even reaming. And work that ejector rod with some purpose.

 

[Remllez]

How's it shoot? I wouldn't mess with it if it shoots good,you might get one that's worse. I agree the short rod and hot loads may be contributing factors but you may have to clean it real well and pop the ejector good to empty. Mr.Borland brings up a good point about the forcing cones and the saying that Mr Jordan coined.

 

[Old Fuff]

Yup! I know about expanded chambers, as does Tuner, and without doubt so does Smith & Wesson. The chambers were not only bored, reamed and polished, but finished by burnishing - so cases shouldn't stick.

But they have to be kept clean if you also shoot .38 Special cartridges with lead bullets in the long Magnum chamber. I advise you get a .40 caliber bore brush to clean the chambers, chucked in a slow RPM drill press or electric hand drill. Do not use this combination on the barrel!

If cleaning the chambers doesn't cure the problem, send the revolver back to S&W, and they'll guage the chambers to see if they are (or are not) expanded, or they might have you just send in the cylinder assembly for inspection. In any case this condition isn't detectable by eyeballing in most cases.

If they are, expect to pay for a new cylinder plus labor. Chambers don't expand unless subjected to excessive pressure.

 

[Jim K]

In a closed container, pressure exerts itself in all directions equally, so if the pressure is very high, it can be enough to stretch the cylinder wall. Very high pressure will burst the cylinder wall, and usually blow off the top strap, but lesser, but still too high, pressure will expand the chamber so it is larger at the middle and front than at the back. When the case expands into that larger part, it is very difficult to extract through the smaller rear part.

Not real common, and it is a bit of a fluke even with a Model 19 and factory .357, but some folks load .357 hotter than the factory, so if you are not the first owner of the gun, he might have traded away trouble.

Jim

 

[spm]

I guess I should have said that I have cleaned it really well. I took a tornado brush to it, but I didn't use a .40 cal size or put it in a drill, as Old Fuff suggested. I'll try that one. One of the guys that runs my range suggested getting some jewelers rouge(?) and using a mop on an electric drill to polish the chambers. Didn't try that because I was afraid I might do more harm than good, until you all suggested similar things. Guess I'll try that, too. Sending it back to S&W would be my last resort because, as Remllez said, it does shoot well, so don't mess with it. Having said that, it seems to be getting worse. I can hit the ejector rod until I poke a hole through my hand and it won't eject. Thanks for your help


"We deal in lead, friend.".

 

[1911Tuner]

Quote:

"Chambers "expand"? I'm no gunsmith, but I've not heard that one before.."

Maybe "stretch" would be a better term...and it doesn't take overpressure to do it.
A lot of high-but-within SAAMI specs can have a cumulative and detrimental effect.
.357 caliber K-Frames have thin cylinder walls. Stress them enough...often enough...and they'll stretch.

I've seen .45 Colt new Model Blackhawk chambers stretched from a steady diet of "Ruger Only" loads found in loading manuals but never okayed by Ruger. Call and ask them. Like the Model 19s and other K-Frame .357 Magnums...Moderation is the best policy.

On the Model 19 that I referenced...you couldn't see the bulge in the chambers, even with a strong light. It showed up on the brass when I was finally able to get it out. There were only two, but that was enough to lock up the ejection solidly. Had to knock the cases out with a dowel rod and a hammer.

 

[Owen Sparks]

Polish the chambers? If they are a little fough they can siez the brass.

 

[BCRider]

On the suggestion of jewelers rouge on the barrel mop? DO NOT DO THAT! ! ! ! !

The JR is an abrasive compound which means it'll remove some metal. But doing it with a bore mop means that you're not removing metal in a controlled manner. Both the part that is maybe already too big will get bigger at the same time that the tight portions get bigger. And besides, if your cylinder has stretched in the middle then using the JR and mop is just going to remove metal and enlarge a chamber that is already too large in the middle already.

All in all it's not a good idea at all and I would never do it to any gun. There's better ways to slightly ease a tight chamber. But if you're dealing with a misshapen chamber, such as would happen if the middle stretched out, then polishing with any abrasive of any sort is not the right answer.

 

[spm]

Yep. I replaced the cylinder on a Model 19 for that very thing just last year.

K-Frame .357 Magnum revolvers are marginal when it comes to full-power .357 ammo.

When the Model 19 was developed at the behest of Bill Jordan, the advice from Jordan and Smith & Wesson was:

".38s for practice and .357s for business."

It makes just as much sense today as it did then.

1911 Tuner,
Did you send your gun to S&W to replace the cylinder? How long did it take? May I ask how much it cost? And finally, how does the gun shoot with the new cylinder?
Thanks for your help,
spm

 

[spm]

On the suggestion of jewelers rouge on the barrel mop? DO NOT DO THAT! ! ! ! !

The JR is an abrasive compound which means it'll remove some metal. But doing it with a bore mop means that you're not removing metal in a controlled manner. Both the part that is maybe already too big will get bigger at the same time that the tight portions get bigger. And besides, if your cylinder has stretched in the middle then using the JR and mop is just going to remove metal and enlarge a chamber that is already too large in the middle already.

All in all it's not a good idea at all and I would never do it to any gun. There's better ways to slightly ease a tight chamber. But if you're dealing with a misshapen chamber, such as would happen if the middle stretched out, then polishing with any abrasive of any sort is not the right answer.

BC Rider,
That was pretty much what I was afraid of, which is why I didn't do it. I'm glad you came back with this one. I won't.
Thanks for your help,
spm

 

[MrBorland]

Maybe "stretch" would be a better term...and it doesn't take overpressure to do it.
A lot of high-but-within SAAMI specs can have a cumulative and detrimental effect.
.357 caliber K-Frames have thin cylinder walls. Stress them enough...often enough...and they'll stretch.

Good info, thanks.

Is this true of stainless .357 k-frames as well?

Does the stretch eventually reach a point where the gun will kaboom? Or will the shooter know something is amiss well beforehand?

And what of the throats? Ejection of cases is one issue, but if the throats expand (or contract?), is accuracy affected as well?

 

[1911Tuner]

They rarely kaboom unless there's a double, or...as is distinctly possible with Bullseye...triple charges. Most of the time, the brass just expands to fill the bulged section. Sometimes a case will split or burst, but the gun usually endures it. This is the reason that I rarely use Bullseye, and when I do, I'm real careful to visually check and double-check the charged cases before proceeding. Getting careless with Bullseye has turned more than one fine gun into a grenade.

Accuracy shouldn't be affected, or at least not enough to make a practical difference.

 

[rcmodel]

I would suggest you use the drill, .40 brush & solvent as Ol Fuff suggested.

Then clean & dry the chambers with clean patches.

Then, hold the cylinder up to a strong light and look through each chamber.
You should be able to see any bulge by a difference or shadow in the reflected light.

Pay special attention to the areas right over the locking bolt cuts.
That is the thinnest section of each chamber sidewall, and if there is chamber damage at all, it should show up as small dents or divots right over the locking bolt cuts.

If you see that, your cylinder is toast.

My personal bet is that you still have hard carbon fouling rings in the fronts of the .357 chambers from shooting shorter .38 Spl in it.
They can be very hard to see if you don't know what to look for.
The drill, oversize brush, and solvent will take them out in short order though.

In extreme cases, I use 0000 grade (Super Fine) steel wool wound on the bore brush.
No, it will simply not harm the chambers, but it will sure clean them down to only what S&W intended too be there in the first place.

rc

 

[SaxonPig]

I wouldn't take a 19-5 as a gift. Nothing but QC problems with these. I have a 41 year old 19-3 that's a retired cop gun and has fired thousands of full power 357s without a hitch. But it seems like every other 19-5 that comes along is broken.

 

[Remllez]

I agree with RC about his method of deep cleaning of the charge holes. I have a couple Smith K-22's that seem to foul easily causing the very thing you are describing...#4 brass wool on a .25 caliber brush shines them up like new and helps the ejection problem greatly.

 

[svtruth]

I don't know if .38s have enough power, but the advice on firing .45s in a .454 is: Don't.
The explanation is that the shorter round fire cuts a slight ring in the chamber at the end of the case, and then the longer, higher pressure round fire forms the case into that annulus, resulting in difficult extraction.
Good luck.

 

[1911Tuner]

svtruth...Thank you. I've cautioned about that point for years, and very few people have accepted it.

If the forcing cone will erode, and the topstrap above the gap will flame cut and erode...so will the area of the chamber behind the throat.

 

[gamestalker]

I have a couple of K frames and they get a steady diet of full house magnums, H110/296 loads to be specific, and I have never had that issue. My 66-2 has had well over 5 K of nothing but the above loads and the 66-5 slightly less than that.
I don't shoot 38's through mine because it can and in fact will put pressure cuts behind the throat which will allow the .357 brass to expand into the cut and cause difficult extraction. After just a few cylinders of 38's and the beginning of the damage can be easily seen.
Before I would go replacing the cylinder I would have the cylinder measured. I read on some where that S&W put 250,000 125 gr. H110/296 loads through a K frame and nothing failed or even got loose.
I'm with most other's that a really good cleaning and a quality polishing job should help along with avoiding shooting 38's through it.
You didn't really indicate fully if your using hand loads or a factory round?

 

[rcmodel]

Neither have I.

I have been shooting and working on all manner of revolvers for going on 50 years now, and I have yet to see a revolver chamber with any sign of erosion in the throats or chambers.

Gas cutting on the top strap? Yes!
Worn out bores? Yes!
Chamber erosion? Nope!

My understanding of the warning about shooting .45 Colt in the Freedom Arms .454 relates to them having minimum spec chambers, and running very high pressure in comparison to most all other magnum calibers.

A .45 Colt hard carbon ring left in the chamber would prevent the full length .454 case from expanding enough to release the bullet.
That would drive chamber pressure sky-high.

rc

 

[harvester]

Clean it up good with the drill brush and solvent as above. If it cleans up, and works better, good. If not, it has another problem anyway and I doubt you could hurt it unless you really go overboard with the time spent with drill.

 

[spm]

Factory loads only.

 

[351 WINCHESTER]

I bought a new 66 in the early 80's. I tried to master shooting it d/a with full house Remington 125gr. magnums. After about 350 rounds the gun was out of time and the forcing cone was cracked. S & W replaced the barrel and cylinder and retimed it foc.
I don't know what powder Remington used, but I doubt it would have made any difference. These guns were never meant for a steady diet of magnum ammo. They will probably fare much better with today's downloaded ammo as the ammo I was using had a reputation of being hot and it was.