S&W-617 sudden loss of accuracy - what happened?


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IMtheNRA
October 24, 2011, 02:17 PM
I've had this revolver since around '95 and have fired at least 50,000 rounds from it. Last year, it went back to S&W due to spitting lead and loose lock up. They fixed the lock up, reset the barrel, and recut the forcing cone. I also had them install a wide trigger and wide hammer. The smith at S&W made the trigger a little lighter at my request. After it came back, the gun has performed flawlessly for the past year.

On Saturday, the revolver suddendly became terribly inaccurate. My usual 1 inch groups from 12 yards became 4 to 5 inch goups!

There was no gradual degradation in accuracy - this seems to have happened since the last range trip with this gun. I checked the sights and they're not loose, there is no visible damage to the crown.

What do you think could have caused such a sudden and severe loss of accuracy?

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rcmodel
October 24, 2011, 02:19 PM
Check the bore and forcing cone for severe leading.

Try another brand of fresh ammo.

One or the other is about all it could be if it still works right otherwise.

rc

IMtheNRA
October 24, 2011, 02:59 PM
Rcmodel - thank you for the hint. I found something weird. While there is no noticeable lead build up, and the lands and grooves seem well defined and sharp, there is something about an inch from the muzzle.

This appears to be a dark ring, about the size of a .22 bullet. Futhermore, the lands seem to be marked with a sharp engraving that runs perpendicular to the bore. Like a tiny, sharp double line encircling the inside of the bore, and marking the outermost edge of this dark ring...

I tried to feel this ring with a dental probe, and I am pretty sure the probe catches on this line in the lands. The line is in the lands only, and I don't see it in the grooves of the rifling. I'm pretty sure this is not a good sign.

Could this ring and line be lead build up, or are they the leftovers from an un-noticed squib? If this was a squib that later got shot out, could it have damaged the bore?

Short of sending the gun back to S&W for repairs, is there another diagnostic step that I can take? (The gun had a very thorough cleaning prior to Saturday's shooting session).

rcmodel
October 24, 2011, 03:06 PM
Did you use a new bronze bore brush and solvent when you cleaned it??

If it is ringed from a stuck bullet squib, you should be able to see it on the outside of the barrel.

Look down the sides of the barrel toward a strong light and see if you can spot a ripple in the outside finish reflection that matches up with the anomaly in the bore.

If so, the news is not gonna get any better.

rc

Jim K
October 24, 2011, 03:10 PM
Sounds like you had a squib round that left a bullet stuck in the bore, then fired another round behind it, bulging the barrel. You can try using a brass pick or brass screen wire on a rod and see if you can remove the lead. You can also feel the outside of the barrel for a bulge.

If the barrel is bulged, beyond removing what lead may be in the barrel, I don't know any solution other than replacing the barrel. But first, I would get the lead out. Sometimes a gun will survive a barrel bulge and continue to shoot well; sometimes not.

Jim

IMtheNRA
October 24, 2011, 03:18 PM
Yup... I see it now. There is a barely perceptible bulging of the barrel, visible only when viewing the barrel from the muzzle end with a strong light on the barrel.

The bulge does match up with the locaton of the dark ring inside the bore. :(

I did not realize that a .22 squib could develop enough force to bulge such a thick barrel... Is this severe loss of accuracy consistent with symptoms of a bulged barrel?

So, what do you think S&W charges to replace a 6" barrel?

WNC Seabee
October 24, 2011, 03:21 PM
ouch. I suspect that very soon you will have a very nice 4.5" Model 617. Cut and crown that barrel, reset the sight and marvel at how quickly that nice short barrel clears leather!

IMtheNRA
October 24, 2011, 03:25 PM
Seabee - that would be great, as I've actually thought of getting a 4" version of this revolver.

However, I don't think it can be cut down, since the front sight is set on a ramp, which forms the forward 1.5 inches of the barrel.

I'll probably ask S&W install the 4" barrel to replace this one.

Walkalong
October 24, 2011, 03:27 PM
Clean the crap out, and you may be surprised how well it can still shoot.

rcmodel
October 24, 2011, 03:27 PM
So, what do you think S&W charges to replace a 6" barrel?
Well, an unfitted 6" 617 barrel from Brownell's is $141.29 retail / $113.03 after my discount.

rc

Jim K
October 24, 2011, 03:30 PM
Will a bulged barrel cause loss of accuracy? I think you have answered that question.

I would call S&W for an estimate. That work would not be under warranty, but they might be nice and send you a shipping label which could save a few bucks.

Yes, bulged barrels happen even with .22's. Most folks don't understand what happens when a bullet encounters a bore obstruction, but the answer is heat. That bullet, even in a few inches, has acquired a lot of kinetic energy and when it stops, that energy is converted to heat. That heat only lasts an instant but is enough to heat the barrel and weaken it, and the pressure does the rest. What puzzles folks is that heat enough to soften the barrel won't even hurt the bluing or cause burn marks on stainless steel. But remember that the heat doesn't last long and it takes time to oxidize the steel.

Jim

IMtheNRA
October 24, 2011, 03:57 PM
Makes sense, Jim K... After waiting on hold at S&W for about 20 minutes, the rep told me that it'll run about two hundred bucks to install the new barrel. That's not bad, but FedEx will gouge me about sixty bucks to ship the gun, which is the part that I dislike the most.

I'll give the bore a good scrubbing around that dark area before sending in the gun, but I have a feeling that I know how this will end :-(

Now, I just need to figure out if I want another 6" barrel or perhaps try a 4" barrel.

David E
October 24, 2011, 04:15 PM
I'm puzzled why a squib was "unnoticed." I can understand inadvertently firing another shot rapid fire and causing the same result by being a 1/2 second too late to stop the next trigger pull. But it wouldve been "noticed" immediately.

I've had one actual rimfire squib (.22 magnum) and knew right away something wasn't right.

Leave it to the gunsmith about how to shorten the barrel and compare replacement vs cutting it down costs.

IMtheNRA
October 24, 2011, 04:26 PM
David E - Using double hearing protection, outside, with other shooters scattered around the club, a slightly off-report of a .22 could sometimes go un-noticed.

The fact that the bulge is located about 5/8 of an inch from the muzzle leads me to believe that there was at least some powder charge in the case, but not quite enough for the bullet to clear the barrel.

Stainz
October 24, 2011, 04:34 PM
I was looking for a better reason... certainly less expensive. Did you just switch to de-caf??

I was shocked at the difference - really can't imagine a bulge in a hefty 617 barrel from a squib. I'd really try cleaning - with new bronze brushes (Use several..). The Lewis Lead Remover, with it's brass screens, works best with .356+" bores. If it persists - and the work was by S&W so it should still be under warranty - have S&W pick it up and look it over. Overnite FEDEX for them is ~$14 - if they deem it's your fault, that's all you'd pay - back to you.

Stainz

IMtheNRA
October 24, 2011, 04:45 PM
Hello Stainz, I intend to give it a huge scrubbing this afternoon, as soon as I get some brand new .22 brushes. The bulge is clearly not a warranty issue and S&W did not offer me a shipping label. About a year ago, Fedex charged me almost sixty bucks to ship the gun to S&W and I'm pretty sure their prices did not go down...

I'm afraid I don't understand your question about "de-caf".

Until a couple of hours ago, I could not imagine a bulge in this beefy barrel either. However, it really is there. Hard to see unless the light is just right, but it is there nonetheless :-(

MrBorland
October 24, 2011, 05:28 PM
However, I don't think it can be cut down, since the front sight is set on a ramp, which forms the forward 1.5 inches of the barrel.

I'll probably ask S&W install the 4" barrel to replace this one.

You can cut it down, and have a Weigand interchangeable sight base (http://www.jackweigand.com/interfs.html) installed. In addition to allowing you to cut your barrel to a custom length, this little beaut lets you change your front sight in seconds - from fiber optic to gold bead, to standard Patridge, depending on your application. It extends the versatility of an already-versatile gun.

whalerman
October 24, 2011, 05:33 PM
This was a very interesting thread. I learned a lot I didn't know. Thanks.

rcmodel
October 24, 2011, 05:35 PM
That Weigand interchangeable sight base is what I would do.

Make a 5" out of it, so you don't have to make the decision between a 6" or a 4"!!

rc

IMtheNRA
October 24, 2011, 05:43 PM
Whoa!!!! I had no idea this option even existed! I'd love to have a sight system like my 627! That is a GREAT idea! Thanks a ton!

Weigand is closed for the day now, but I'll call them in the morning to see if they offer the service of cutting down the barrel and installing their front sight base.


Thanks a lot, MrBorland! :-)

Hondo 60
October 24, 2011, 06:10 PM
Instead of having Fedex gouge you, why not talk to a local gun dealer?
They can ship via US Mail.
It costs me less than $30 to have a gun shipped.

MrBorland
October 24, 2011, 06:30 PM
Call around, and you might find a local 'smith who can do the work. I know SDM (http://www.sdmfabricating.com/) and Fletcher (http://www.fletchercustompistols.com/smith_wesson_custom_revolvers.htm) also advertise they can do the conversion.

Here's a neat little photo essay on a conversion:

http://www.sdmfabricating.com/4_conversion.html


Instead of having Fedex gouge you, why not talk to a local gun dealer?
They can ship via US Mail.
It costs me less than $30 to have a gun shipped.

Yep - that's how I ship. Easier and cheaper.

highlander 5
October 24, 2011, 06:56 PM
Wait a sec,the gun shot fine till S&W did work on it,THEN the accuracy went down hill? Am I missing something here or does it sound like S&W did the damage to the barrel?

David E
October 24, 2011, 08:13 PM
Yes, you're missing something.

OP, another vote for a 5" barrel, it's perfect!

Stacer
October 25, 2011, 12:16 AM
I absolutely LOVE the 4" barrel on my K22, but 5" would be right on.

IMtheNRA
October 25, 2011, 01:26 AM
I can't tell you how glad I am to have screwed up this gun :neener:

I spoke with a local smith who can cut the barrel down to five inches and install that sight base. We spoke on the phone and he sounds very smart, technically advanced, and passionate about the project. I want to meet him in the next few days, just to make sure, and then we can get this project started.

Five inches (or so) would be the PERFECT length for the 617.

Before and after pics will follow :)

Stainz
October 25, 2011, 05:51 AM
The 'de-caf' remark was an attempt at levity. One AM at the range ~2 yr back, after a caffein-free soda only at breakfast, I was extremely shakey - even had a headache. I couldn't hit the broad side of a barn, much less 'group' well. A stop at the range store for a pop and some chocolate and the headache abated. At least I could drop the SPC metal plates after a bit. Perhaps a silly question, but how is your accuracy/marksmanship with other caliber revolvers... any change there?

If you send it back to them (S&W) to be evaluated, they will send you a prepaid label. You may have to ask for it. Their charge for shipping is a lot less than you'll ever find, too. Be honest in your accompanying letter. Additionally, you'll get the barrel you want - and keep your warranty. Your warranty will end when that barrel gets chopped by your local 'smith. Still, it's your decision.

Stainz

MrBorland
October 25, 2011, 10:10 AM
I can't tell you how glad I am to have screwed up this gun

I spoke with a local smith who can cut the barrel down to five inches and install that sight base. We spoke on the phone and he sounds very smart, technically advanced, and passionate about the project. I want to meet him in the next few days, just to make sure, and then we can get this project started.

Five inches (or so) would be the PERFECT length for the 617.

Before and after pics will follow

Great news. We'll look forward to the pics. And a range report, too, eh?

BTW, have the 'smith look the gun over to see if there might be some other explanation for it's lost accuracy. It'd be a shame to pay for work that wasn't needed and didn't fix the problem.

waidmann
October 25, 2011, 09:42 PM
Another solution is to bore the barrel from the muzzle oversized from the muzzle end past the bulge and re-crown internally.

ClemY
October 26, 2011, 09:20 AM
5" is the perfect barrel length for a full lug 617. I cut down a 6" 617-5 a couple of years ago and it is perfect.

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