642 b/c gap .021" Okay by S&W ???

[fourdollarbill]

I previously posted a thread on a 637 that started this whole thing. I'm new to revolvers and found how important the cylinder to barrel gap is. On my new 642-2 the cylinder gap is .008" at 12 oclock and .021" at 6 oclock. Yes .021".
The confusing part is... When I emailed S&W with this info they told me the gap is fine.

Here is a cut and paste from my email.


RE: 642 repair question‏
From: Ogonowski, Mel ([email protected])
Sent: Tue 12/16/08 8:30 AM
To: 'Gary' ([email protected])
hi
yes the gap is fine
thanks
mo

-----Original Message-----
From: [email protected] [mailto:[email protected]]On Behalf Of Gary ******
Sent: Saturday, December 13, 2008 8:50 PM
To: Smith & Wesson Support
Subject: 642 repair question

To whom it may concern, I bought a new 642 revolver from a local shop and found the gap between the cylinder face and the barrel cone is .008" on the top and .021" on the bottom. The barrel is cut at an angle. It shoots well. And no problems are accuring that I know of. But everybody I talked to said that gap should be no more than .006" total and it should be absolutly straight. Does it need fixed? Also I just stopped at a local gun retailer and looked at a new 642 and it looks exactly the same with a angled cut. I attached a picture in .jpg. Can you tell me if it is okay or not.

Thank you,
Gary ******

What are your thoughts on this.

I replied and asked if I can hire them to "set it back" to a tighter spec at my cost. I'll keep you updated.

 

[krs]

Nah,
I have a 442-1, CEL prefix, and I have a Mititoyo set of feeler guages.

The gap in my pistol is exactly .008" snug sliding fit at top or bottom of the barrel and the next .009" guage will not enter the gap at all.

I can not undertstand how a S&W representative could tell you in writing that the gaps you detail are 'fine'.

If this is the pistol which you photographed and posted the photo of, I thought that the centerline of your cylinder, the axis, was not straight in the frame. I based this on what little I could see of the alignment of the ejector rod with the underside of the barrel. That, with the gap as shown, gave me to think that there may be a break or stretching of the lower portion of the frame of the pistol. This is not a conclusive assessment on my part as the view I had could have been effected by shadows or even by the characteristics of a wide aspect lens used at a close distance. Both could have distorted the true alignment of your pistol but even so it was plain to see that the gap at top was considerably smaller than the gap at bottom.

Frankly, I would not shoot that pistol.

Is there an independent gunsmith who you could take it to and ask what he thinks? It would be much easier to find what's going on if the pistol was in hand.

 

[fourdollarbill]

I have tried a few local Smiths but they do not have the proper tooling for this.

I'm very certain the cylinder is square with the frame. The barrel is absolutely cut at an angle. I had tried to call S&W monday and today and was asked to leave a message. I'll keep tying...

 

[fourdollarbill]

I just got through to a S&W serviceman and he told me the factory "go no go" gauge was set at .003" to .010". He is going to send me a call tag to ship it out and get it fixed. He advised to say on the cover letter that the b/c was filed crooked and I would like it straightened out. Of course i'm very pleased. The only bummer is that they are shut down for two weeks and it will take up to ten days to fix it and the call tag takes about 5 days.

It may take a month but it still beats having a gun with a spray pattern.

 

[Jim Watson]

A wide, angled cylinder gap is not the mark of a quality revolver.
(Glad you finally got in touch with someone who realized that.)

The factory cure will probably be to replace the barrel, it would be less expensive to them than the gunsmith cure below.

The gunsmith cure would be to set the barrel back a turn to allow its shank to be squared with a standard .006" gap. This would require the barrel to be removed, the shoulder set back enough to allow it to be screwed in a turn more, the shank reworked, and the extractor rod and center pin shortened the same amount.

Either way, there is some risk of cracking the aluminum frame by running the barrel out and in. Good luck.

 

[krs]

I just checked my wife's 442-2 just for fun and it measures the same .008" top and bottom that mine has, posted above.

Neither barrel shows any obvious sign of having been fitted by filing although a strong light and a good magnifier does reveal slight tool marks in a crossframe direction that were done either by expert light filing or a fine cutting machine tool designed for the purpose.

 

[clutch]

Old thread but I was checking my gap on a new 442-1. I have 0.008" and was wondering if that was in spec. I took the measurement to help determine at a future time if I have overloaded it.

From reading this, I'm good to go atm.

Clutch