Newer S&W Question

Status
Not open for further replies.
R

rcmodel

Member in memoriam
Joined
Sep 17, 2007
Messages
59,074
Location
Eastern KS
A friend ask me a question I can't answer today.

He has a new Model 69, and it has 2 small blind holes inside the ejector rod shroud on the barrel.

My Model 625-6 has 1 small blind hole.

What are they there for???? :confused:

Model 69.jpg

rc
 
Stuff like this is part of why I check this site several times a day. There's always something interesting that I'd never noticed before.

My new 640 has one hole too. I started to check my 36 and remembered that it doesn't have a shroud. Pulled a Taurus snubnose out of the cabinet and it has a mark in the same place, but it's an X instead of a hole. Taroman's answer seems likely to me.
 
Those look more like bleed holes than locator holes. Are they actually blind or could there be a channel to the inside of the shroud around the barrel?

Jim
 
My ten yr old N frame has no holes or marks in there.

If they go somewhere I'd suggest that they are coolant holes but they don't look like they do.
 
Howdy

Here are similar holes in the extractor shrouds of a Model 686-6 and a 617-6.

They are not through holes, they are just very shallow holes, almost countersinks.

mystery%20hole%20686-6_zpsgbtmuf7i.jpg

mystery%20hole%20617-6_zpslkctwapk.jpg



I have done a fair amount of CNC work, and I have never heard of an 'indexing spot'. They are not spot faces. Spot faces are flat features milled onto the surface of parts, usually castings, for a reference surface. They could possibly be the remnants of tooling holes that were machined away when the groove was cut, but for the life of me I can't figure out why tooling holes would be useful in that position.

I have lots of Smith and Wesson revolvers, some made on CNC equipment before the lock/mim parts era, and these two are the only ones that have these features in the groove of the extractor shroud. The 617 was made in 2003, the 686 was brand new last year. Clearly, S&W is not going to expend extra effort machining useless features into their parts, but I am a bit stymied as to what these features are.
 
As Driftwood says, they are NOT CNC indexing marks. I also have done CNC, and in a production setting the workpiece is not dismounted from a dedicated chuck/potchuck, then remounted elsewhere. Unless the intention was to waste money.
 
My new production 586-8 has no such marks or holes.

Maybe they're gas ports activated during the firing of the last round in the cylinder to blow the cylinder open, aiding ejection and reloading?
 
Last edited:
I'm not buying the CNC index marks either.

Why would they put then in there when it's the first thing that has to be hogged out early on???

I thought maybe they drilled a series of small holes to make coolent fluid pools in the thick metal during milling the slot?

But that seems unlikely too.

Drilling tiny holes 1/2" deep before milling the clearance slot out wouldn't be that easy to do for little gain.

I thought about calling S&W Customer Service and asking them.
But I doubt the girl that answers the phone knows either.

rc
 
Very interesting. I noticed this marking on the inside of my M&P .40's slide. I know - it's not a revolver - but it is a S&W product. There are five or seven of these shallow holes in a double-column pattern. ::. I have thought about asking what they are, but never got around to it. I would bet that the holes in the revolvers serve the same identification purpose as on their autoloaders.

I hope we can find out. Now I'm super-curious.
 
Well, I called S&W, and got in three people deep before finding one that knew what they are for.

Seems they are the modern day equlivlent of the old assembly marks.

They indicate which CNC work station made the barrel.

1 hole is machine #1, 2 holes is machine #2, etc.

rc
 
Thanks RC. Mystery solved. Sort of like scamp marks.
th_ScampIndexMarks.jpg
[/URL][/IMG]
 
Last edited:
And thanks to 243winxb for the cartridge case Scamp mark photo.

I never thought about what they were for either!!

I Still have a lot of gun stuff to learn!

rc
 
Thanks RCmodel.

I keep telling people to buy S&W over Taurus.

1) Superior material (transfer bar always break on Taurus)
2) Superior design (more internal safety features)
3) Buy 'murican.

Off my soapbox.
 
Status
Not open for further replies.
Back
Top