Stepped 357 chamber before the forcing cone. Fix?

[BK7saum]

I loaded and shot some snakeshot loads in my s&w model 60. The cases came out with the appearance of an indented ring near the forcing cone. After some cleaning and further investigation, it is not a ring, but a step from 0.3805" to 0.374" None of my other smith revolvers have the "step".

Should send it back to S&W, or get the cylinder reamed with a 357 reamer to clean up the step?

Would you worry about the step?

268117268118

The 2 cases on the left were fired in a 686 and a model 19.

[mattw]

Did they cut it for 38 Special? That really looks odd, like something was not finished at the factory.

[MT Gianni]

Model 60 was originally a 38 Special, IIRC. Did someone do a cylinder swap and represent it as 357? Ore you the original owner? How old is it?

[BK7saum]

This is a newer model 60 3" adj sight with Hillary hole, a factory 357, maybe a 60-15., havent looked in a while.

[BK7saum]

I have had it for maybe 10 yrs, bought new by me.

[mattw]

Good catch MT Gianni, I was thinking of the 66 and glossed over the model number. But, I do think they made 60's in 357 as well.

[BK7saum]

Just never noticed how the cylinder was cut before

[mattw]

That definitely is not right. A trip home may be in order, unless you feel like paying for the repair.

[DougGuy]

You could send the cylinder and let me get pin gages to the chambers to determine if the ridge is under spec. If it isn't a finishing reamer won't remove it unless it is a special order reamer made just for that cylinder. Most 357 cylinders are .381" at the case mouth, with a .358" loaded that leaves .023" then subtract the brass (each side) which if the brass is .011" on the case wall thickness, you have .002" left, or basically .001" on each side. If the ridge was under spec, you likely couldn't load a .358" and get it to chamber.

How did you determine the measurements you listed? According to your figures, a finishing reamer SHOULD clean that up.

[BK7saum]

Doug Guy, the measurements listed were the negative impression from the fired 357 max shotshell. I have a set of - pin gauges, just haven't gotten to that point yet. So allowing for brass springback, The step ID might be around 0.373, but by comparison it is a 0.003 step tighter than the chamber.

This step is forward of the location of the mouth of a .357 mag case and is more like a throat before the forcing cone.

[BK7saum]

I lost my first post I typed out, The length to the step is around 1.322 +/-

[nhithaca]

I would return it to the factory for reaming. Just don't tell them you are using Max cases in a Mag chamber!

[44MAG#1]

How long are the cases?

[BK7saum]

The step is forward of the location of a 357 mag case.

[bigted]

If that "ring" is ahead of a proper 357 mag case, then you should never see it while shooting normal .357 rounds.

Wondering the why of using the MAX cases? No condemnation here ... just wondering the why.

Next question is ... do your regular 357 rounds shoot accurately?

[dtknowles]

I thought the forcing cone is in the barrel and what we are looking at is the throat. That step is small enough that the bullet should never touch it unless you use 38 specials and the bullet gets a little sideways before it gets into the throat. At 0.374" that throat seems very loose for bullets sized 0.358" but I would guess that it tapers down to something smaller toward the front. Usually you want size bullets to the throat diameter.

Tim

[Mr_Sheesh]

OP did say they were making snakeshot loads, that is why the max cases.

[W.R.Buchanan]

UH??? aren't those "ridges" the "Throats" of the Chambers?

Cylinder Throats are usually .001 bigger than the Groove Dia. of the barrel,,, and.001 smaller than your boolits,? .357 grooves, .358 throats and .359 boolits? or whatever.

But,,, In any event, I don't believe that fired brass is going to be an accurate way to measure Throat Diameters and base any lasting decisions on.

Pin Gauges please, then we'll know for sure what you've got.

How many rounds have been fired thru that gun,,, maybe thousands? Those ridges didn't just grow in there lately? Ain't Broke, Don't Fix!

Just sayin'

My .02

Randy

[BK7saum]

I have pin gauges, just haven't pinned it yet. This rebolver has seen less than 500 rounds, more likely 200-300. However, it will be about a 0.003" step in the chamber before the funnel to the throat. Really saw no reason to pin gauge it, it shouldn't be there to start with.

Yes, this is the area in front of the throats of the cylinder where the chamber transitions to the throat. I have never seen this in any other revolver. I am wondering just how the heck did this get machined this way. I probably would have never noticed except for stepped brass in my snake shot loads.

[BK7saum]

S&W is supposed to send me a shipping label. Well see what they have to say.

[km101]

Had a similar problem with my 60-15. One hole had a .015 constriction about .030 from the end of the cylinder. The other 4 holes were fine. That hole appeared to not be fully reamed. Sent it back to S&W and they fitted a new cylinder, no charge. That greatly improved accuracy as the constriction caused a consistent flyer. It now shoots better than I can hold.

[BK7saum]

km101,

Good to hear that they took care of you. I'm not sure why the chamber itself has a step. As far as I remember, the throats themselves are consistent.

[BK7saum]

Well it went back to S&W and came back worse than it was. Now it appears that the 0.004" step is still there, the funnel to the throat is not a smooth transition and now there is a 0.008" step in the throad itself the step goes from 0.375" to 0.359".

The paperwork says that they replaced the cylinder and yoke. Where they got the cylinder I dont know, maybe the junk parts bin?

I dont know how S&W could take it in, see that something needed to be fixed and put in a worse part than what was in the gun to start with.

[Thumbcocker]

IMHO S&W are a pale shadow of what they once were.

[DougGuy]

Well it went back to S&W and came back worse than it was. Now it appears that the 0.004" step is still there, the funnel to the throat is not a smooth transition and now there is a 0.008" step in the throad itself the step goes from 0.375" to 0.359".

The paperwork says that they replaced the cylinder and yoke. Where they got the cylinder I dont know, maybe the junk parts bin?

I dont know how S&W could take it in, see that something needed to be fixed and put in a worse part than what was in the gun to start with.

Sheesh unbelivable! I'd sure get somebody on the phone and send it back again!

[500aquasteve]

You waited 8 weeks to have it made worse. An 0.016” change to 0.065”

I had my $1700 3.5” revolver sent to SW to have repaired due to the cylinder smacking the top strap. It has been over 6 weeks now I am afraid of what I might have returned to me. It has less than 500 rounds and is a 500

[BK7saum]

This is before being "FIXED" by S&W
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This is after being FIXED
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Not sure how well the photos show up, they had to be reduced to get them uploaded.

[megasupermagnum]

I can't quite see. Is that still a step?

[DougGuy]

Wow that certainly looks quite borked. I'd be all about somebody there, we'd be on a first name basis before it was done.

I have a couple of 357 finishing reamers but by the looks of it they might only reach to the beginning of the step, but that's just guessing. You could send the cylinder and see but again, I'd be up somebody's butt at S&W to get this fixed. Again.

[BK7saum]

Yessir. I could've sent it to you the first time and a finish reamer should have cleaned it up. But not now.

[DougGuy]

Hmm.. If you were to get a 38 SPL cylinder fitted to it, then send it and have it reamed to 357, at least it would get done nice and proper.