S&W Model 14 soured

Hello Folks,

My friend brought his 6" Model 14 to me. He said that for more than 30 years it has been the most accurate revolver he has owned. Then one day recently the accuracy went away. The sudden change made me think of a crack. I took the revolver home and examined it under bright light with high magnification, and could find none. He said the gun has only fired 148 gr and 158 gr cast bullets loaded to target velocity. The only thing I found was some lead buildup in the chambers. I thoroughly cleaned the gun and mounted a 2x pistol scope (it was already drilled and tapped). Using leather sandbags on a concrete bench, five shot groups were between 2-1/2" and 3-3/4" at 25 yards. My own Model 14 shoots around one inch. I reexamined the gun last night and can find nothing amiss.

What else should I look for?

Thanks, Tom

One thing you could look for is a bulged barrel. The bullet from a squib load gets stuck, or the skirt from a wadcutter separates and remains in the barrel. The shooter doesn't realize what's happened, along comes the next round and clears everything out but the pressure created by the obstruction causes the barrel to bulge. Aside from the obvious, look for a dark ring inside the bore. There are a lot of other things that could be going wrong but this could explain a sudden change.

Cylinder timing. Is it shaving lead at the forcing cone? Normally if so it will have heavier fouling on one side of forcing cone. Old school guys would take a piece of paper and put it around revolver and fire a shot. If shaving lead it will splatter on the paper and also perforate if bad enough. Use new sheet for every cylinder fired. I can’t count how many times I’ve been hit in the face Shooting next to a revolver that was out of timing. So this is my guess.
Jon

along with Jon's suggestions.
Try it using double action also, i've found that if the timing is off it will really show up that way.
also, have you run the chore boy or lewis lead remover thru the barrel to completely remove any lead deposits?

John McCormick wrote:One thing you could look for is a bulged barrel. The bullet from a squib load gets stuck, or the skirt from a wadcutter separates and remains in the barrel. The shooter doesn't realize what's happened, along comes the next round and clears everything out but the pressure created by the obstruction causes the barrel to bulge. Aside from the obvious, look for a dark ring inside the bore. There are a lot of other things that could be going wrong but this could explain a sudden change.

I cannot detect a bulged barrel.  No visible ring, and a tight patch feels smooth from end to end.

Jon Eulette wrote:Cylinder timing. Is it shaving lead at the forcing cone? Normally if so it will have heavier fouling on one side of forcing cone. Old school guys would take a piece of paper and put it around revolver and fire a shot. If shaving lead it will splatter on the paper and also perforate if bad enough. Use new sheet for every cylinder fired. I can’t count how many times I’ve been hit in the face Shooting next to a revolver that was out of timing. So this is my guess.
Jon

Next time at the range I'll try this test.

james r chapman wrote:along with Jon's suggestions.
Try it using double action also, i've found that if the timing is off it will really show up that way.
also, have you run the chore boy or lewis lead remover thru the barrel to completely remove any lead deposits?

Yes, I've removed all lead.  There was very little in the barrel, and some in the chambers.  I will try double action shooting with Jon's test.

Thanks, Tom

A bent crane could do it. Cylinder gap goes from very tight to significant. This is visible by holding sideways to a light and visually inspecting gap while rotating cylinder.

Len

LenV wrote:A bent crane could do it. Cylinder gap goes from very tight to significant. This is visible by holding sideways to a light and visually inspecting gap while rotating cylinder.

Len

 Hi Len,

The BC gap is tight and uniform, both from side to side and for all cylinders.  The seam where the crane closes into the frame is very tight, obvious old-school quality fitting.  I'm not discounting any suggestions, and reverified what I just said before I wrote it.

Thanks, Tom

Hello,

Why a revolver will stop shooting well can fill a book or two.  I believe it has.  Get Jerry Kuhnhausen's shop manual and do the full check out.  The only time something similar has happened to me was when I lost the two cylinder extractor/star pins....spring tension rotated the star, which would cant the cartridges....accuracy went to h---.

Jim

spursnguns wrote:Hello,

Why a revolver will stop shooting well can fill a book or two.  I believe it has.  Get Jerry Kuhnhausen's shop manual and do the full check out.  The only time something similar has happened to me was when I lost the two cylinder extractor/star pins....spring tension rotated the star, which would cant the cartridges....accuracy went to h---.

Jim

Hi Jim,

That's interesting.  The malfunctioning gun, a Model 14-2, does have two pins, and they are intact and not bent.  But my Model 14-4 (which shoots very well) only has one.  The Model 14-2 star is tight and will not rotate when down on the pins.  The Model 14-4 star will wobble on its single pin, but there are no symptoms on the targets.  I wonder how hard it would be to obtain a pin and install it, as insurance against future problems?

Thanks, Tom

Is there any damage to the crown of the barrel?

+1 on crown.

Jon Eulette wrote:Cylinder timing. Is it shaving lead at the forcing cone? Normally if so it will have heavier fouling on one side of forcing cone. Old school guys would take a piece of paper and put it around revolver and fire a shot. If shaving lead it will splatter on the paper and also perforate if bad enough. Use new sheet for every cylinder fired. I can’t count how many times I’ve been hit in the face Shooting next to a revolver that was out of timing. So this is my guess.
Jon

Today I covered the gun with paper and fired it.  All chambers checked out fine, with no shavings of lead apparent on the paper.  Previously I had carefully inspected the alignment by shining a bright light down the barrel and looking for any eccentricity.  There was none.  Jon's suggestion reinforces the earlier conclusion.  I think the timing is alright. 

Orpanaut wrote:Is there any damage to the crown of the barrel?

No.  The crown has no marks whatsoever.

for s**ts and giggles.

pick one chamber,  fire 5 rounds thru that chamber and see if it shoots accurate or all over the place.

What about the ammo?Handloads or factory?

james r chapman wrote:for s**ts and giggles.

pick one chamber,  fire 5 rounds thru that chamber and see if it shoots accurate or all over the place.

This is something I thought about but subsequently forgot.  It's an excellent idea, and may offer good diagnostic information.  Thanks.

atrfod wrote:What about the ammo?  Handloads or factory?

The ammo is handloaded.  But the ammo is a constant.  The handloaded ammo used to shoot well.  However, I may still get a box of Federal American Eagle 158 gr RN and try it.  Thanks.

Perhaps the forcing cone has eroded over time.  Even target loads can develop issues.  It used to be a standard practice to re-touch a forcing cone during a tuneup.

Not trying to sell anything but this might have some info. https://www.brownells.com/userdocs/learn/Inst-152.pdf

There might be something in this thread that would be useful:
https://www.thehighroad.org/index.php?threads/s-w-617-sudden-loss-of-accuracy-what-happened.621745/

Boxturtle wrote:

spursnguns wrote:Hello,

Why a revolver will stop shooting well can fill a book or two.  I believe it has.  Get Jerry Kuhnhausen's shop manual and do the full check out.  The only time something similar has happened to me was when I lost the two cylinder extractor/star pins....spring tension rotated the star, which would cant the cartridges....accuracy went to h---.

Jim

Hi Jim,

That's interesting.  The malfunctioning gun, a Model 14-2, does have two pins, and they are intact and not bent.  But my Model 14-4 (which shoots very well) only has one.  The Model 14-2 star is tight and will not rotate when down on the pins.  The Model 14-4 star will wobble on its single pin, but there are no symptoms on the targets.  I wonder how hard it would be to obtain a pin and install it, as insurance against future problems?

Thanks, Tom

Hello Tom,

It is an easy fix.  I make my pins out of hardened drill rod....turned, shortened, round the tip and set....never had one come loose again so far.  If you have the old one or purchase a used one; very slightly peen the end, add a little loctite and you will be good to go.

Jim

Thanks Jim.  I'll contact S&W about purchasing a pin.  I don't have access to a lathe.

Wobbley wrote:Perhaps the forcing cone has eroded over time.  Even target loads can develop issues.  It used to be a standard practice to re-touch a forcing cone during a tuneup.

Not trying to sell anything but this might have some info.  https://www.brownells.com/userdocs/learn/Inst-152.pdf

Very interesting read, thank you.

mikemyers wrote:There might be something in this thread that would be useful:
https://www.thehighroad.org/index.php?threads/s-w-617-sudden-loss-of-accuracy-what-happened.621745/

Another very interesting read.  Thanks Mike.

Two things:

Regarding missing or loose pins. Until you get that resolved, leave alternating cylinder charges holes (chambers) filled with fired brass from that gun. As they expand, they actually hold things together pretty firmly between the cylinder and the ratchet or star or doohickey. Try accuracy testing, then switch out until all are tested.

Sudden accuracy fall off, is typically because of a sudden event. You have checked leading, bullet splatter and the crown. Does the cylinder spin freely, when closed and if you pull back on the hammer just slightly and then spin the cylinder?

Next, open the cylinder, get some acetone or similar good cleaning agent that will remove all oil. Get a magnifying glass and look closely the 6 oclock position of the cylinder end of the barrel. At this spot, the thinnest spot on a K frame S&W barrel, there is flat cut on the barrel for clearance when the cylinder is closed. S&W K frame barrels are most vulnerable at that location for cracking. It doesn't take much of a crack and accuracy can fall off quite quickly. Check it out, carefully.

Allgoodhits wrote:Sudden accuracy fall off, is typically because of a sudden event. You have checked leading, bullet splatter and the crown. Does the cylinder spin freely, when closed and if you pull back on the hammer just slightly and then spin the cylinder?

Next, open the cylinder, get some acetone or similar good cleaning agent that will remove all oil. Get a magnifying glass and look closely the 6 oclock position of the cylinder end of the barrel. At this spot, the thinnest spot on a K frame S&W barrel, there is flat cut on the barrel for clearance when the cylinder is closed. S&W K frame barrels are most vulnerable at that location for cracking. It doesn't take much of a crack and accuracy can fall off quite quickly. Check it out, carefully.

Yes, the cylinder does not bind.

I've been studying the breech of the barrel carefully, under bright light and with magnification.  I cannot find a crack, though that was my first thought and continued suspicion.

Hello,

Also study the fired cases.  Primer flow?  Pierced primers?  Unusual expansion/thinning indication headspace issues?  Etcetera.

Jim

spursnguns wrote:Hello,

Also study the fired cases.  Primer flow?  Pierced primers?  Unusual expansion/thinning indication headspace issues?  Etcetera.

Jim

Thanks Jim,  I'll do that.  I'm going to shoot the gun some more tomorrow.  Take care, Tom