New barrel on 686 came off while shooting

[69daytona]

I had a new barrel installed at a local gunsmith on my old 686, changed it from a 6" to a 4" to use as a carry gun.
While at the range Saturday after about 40 rounds of rapid fire using 125gr hand loads the barrel fallowed the last round down range.
At the cease fire I picked it up barrel was clear didnt look like any damage, no cracks in the frame but the last 3-4 threads look stripped out and there is a small gauge on the frame where the just below the ejector housing.
Any ideas what they did wrong? They dont open until Tuesday so I cant do anything until then.

[looseprojectile]

That is unfortunate.
Now we get an inkling of why S&W tends to make them with the thread reduction in the throat of the barrel. They are fit close. Clocking can be problematic.
Not a pinned one?
I would think your gunsmith should eat that one and pronto.
I have cold iron blacksmithed guns for decades and always gave Smith & Wessons a lot of extra care and effort. They deserve it.
Good luck. You should come out whole from this one.


Life is good

[justashooter]

your "old gunsmith" f'd up a new barrel? time to get a new gunsmith. the one you have ain't worth salt.

[scb]

I really find this hard to believe. I'm not saying it didn't happen, I just can't imagine what he did to cause this to happen. The only thing I can guess is that the barrel wasn't timed (clocked) to the frame very closely and rather than fitting it properly by using a lathe he just reefed it on and in the process pulled the threads either off the barrel or out of the frame. Some guys just don't know when they are in over their head.

[leftiye]

Lotta guessing there! Though it is hard to imagine that happening when there are still threads on the barrel.

[Red River Rick]

Lotta guessing there! Though it is hard to imagine that happening when there are still threads on the barrel.

The threads in the frame must have let go then.

Wrong pitch diameter (too small) on the threading job. And or, the smith tightened the hell out of the barrel to index it and pulled the threads to the point of almost failing. It held for a few rounds and then let go.

Could have been a lot worse..................and not to mention a law suit.

RRR

[Bambeno]

Any news on you pistol?

[Big Rack]

Sounds to me the barrel was threaded undersized easy to look at the last digit or so and be off by .01 and if your using an indicator your off .01 x 2. I've also seen parts ruined by .025 because mics weren't verified first.
Although I would think it would feel awful loose putting it together, maybe the internal threads were already mostly gone and just wasn't checked.
Curious to see what happened.

[leftiye]

Threads should be a little tight, (not a little loose) when free turning. There should be some drag, but not enough to require a lot of force. The final tightening maybe fifteen degrees of mash. Final torque shouldn't be more (guessing) than maybe 20 - 25 ft/lbs, or less. Do stop when the barrel shoulder meets the frame and just a little - don't go nuts there. BTW loose barrels (not flopping around, snug, but not very tight) do work fine especially if pinned. If you feel funny about it, locktite.

[quasi]

looseprojectile, the 686 was never made with a pinned barrel.

[Casting Timmy]

Are there some pictures we can see? What ever happened in the end? What did they say when you took it back?

[slide]

I am glad you came out of the deal o.k.

[MBTcustom]

It kills me how inept most gunsmiths are at basic machining skills. most that I have met are lucky to be in business. Crappy lathe, crappy mill, = crappy work. Smith with **** between his ears = dangerous equipment.
I have talked with some of the local gunsmiths asking questions, they get all "religious" when I start asking about tolerances and fits and try to impress upon me how their sacred art is only known by a few and how I should not question their hard earned expertise.
BS!!!!
Most of these jokers wouldn't know a thread gauge if they found it in their cereal! The only piece of machinery they know how to run realy well, is a file!
I have read this thread a few times and it burns me up how someone could ruin a beautiful firearm like this.
Of course, in the smiths defense, we dont know the whole story, It could be that the threads were compromised in some way, in which case it would be hard to get a S&W barrel blank that would allow you to cut the threads oversize.
Who knows? I would think that the smith would have at least made the owner aware of the problem and let him make the call as to how to proceed. Irregardless, its never good when a barrel goes flying down range and you get your name plastered on the WWW.

[TCLouis]

Could it be the frame threads were "pulled" galled on the original installation and internal frame threads partially fell away when the smith took the old barrel off and he hoped all would fit up and stay in place?

Buncha long distance guessing . . . ah ere diagnosis going on here on this one with little info to go on.