686 shallow rifling

[Owly]

I don't have a camera capable enough to take a photo of what I am trying to describe so hopefully I can explain my concern adequately.

In July I acquired a 686-6 Talo seven shot with 6" barrel. This thing has had a bunch of issues. Right off the bat, the laquer finish started flaking off the wood grips. I contacted S&W and they sent me out some replacement grip panels. Then I started having issues with light strikes and binding in double action.

I sent it back to the factory and also asked them to check the forcing cone. It had heavy machining burs around the inner circumference. I should have asked them to check the odd rifling too, but I did not.
S&W replaced the hand and firing pin to correct the double action function issues. They also recut the forcing cone to eliminate the burs.

Everything is fine now functionally, but I still have some... odd looking rifling. Doesn't look like I think it should with sharp lands and grooves. The rifling appears very shallow and smooth. It looks a lot like Glock's polygonal rifling but even more rounded and faint.
To you other current production 686 owners, does this sound right? Does S&W used a different type of rifling in these barrels? It doesn't look like any other revolver rifling I've seen, but I'm not sure it's not supposed to be this way.

To those wondering, accuracy at 25 yards with jacketed bullets is adequate. I managed a five shot 3" group tonight from a rest. With lead bullets, groups really start to open up. Let's just say, I was getting better hits with my SP101 snub than I was with this 6" L frame.

Should I be concerned about the riflings appearance or just let it be?

[pangris]

...how does it shoot?

[bigwheelzip]

It is electro-chemical rifling, and not as crisp as mechanical rifling.

[Owly]

Originally Posted by bigwheelzip

It is electro-chemical rifling, and not as crisp as mechanical rifling.

Interesting
I know nothing about this process. I'll have to research how it's done.

Edit: I see they've been using this method since 1993. Obviously, this is the newest S&W in my collection. The rest are all P&R and all my Rugers have traditional rifling. This ECR certainly looks odd to me but does resemble pics online of ECR rifling. Still think it looks too faint to be functional, but I guess more range testing is in order to prove or disprove my theory.

[bigwheelzip]

A quick description.

Firearms History, Technology & Development: Rifling: Manufacturing: Electro Chemical Machining

[Bob1943]

My new 686 Plus 2.5" has the same shallow rifling. Appears to be normal spec these days.

[BLUEDOT37]

As stated, it has the EDM/ECM rifling & many people mistake it for polygonal rifling, but it's not.

I have a 686-6+ Talo 5". I recently chamfered the crown. Hadn't shot it in a long time but took it to the range the last couple times & with Xtreme 158gr RNFP loads it's been grouping far better than I remember.

Wish I had shot it before, & then after I re-did the crown but I did several guns at the same time & was on a roll, so...

Here's how it looks.

.

686-6 TALO, barrel crown, before


.

686-6 TALO, barrel crown, after


.

686-6(+) TALO 5"


.

Here's the old style rifling (broached) in my 627PC.
.
627-5 PC, barrel crown, after


.

[Owly]

Thanks BlueDot, your pics put my mind at ease. Looks like what I've got. I've got some work to do now finding a lead cast load that shoots well from my 686. You might be on to something with the target crown idea. Perhaps an 11° muzzel crown will help if all else fails.

[BLUEDOT37]

Originally Posted by Owly

I've got some work to do now finding a lead cast load that shoots well from my 686... Perhaps an 11° muzzel crown will help if all else fails.

I gave up on shooting lead bullets in my 686; leading just past the forcing cone. Before I chamfered the muzzle I chamfered/lapped the forcing cone (roughly cut & abrupt transition) but no meaningful difference.

Worked up some loads for the Xtreme's, with various powders, & I'm tickled with them. Now I use them in all my guns.

.



.