question about marks on rifling Mod 17-6

[islandguy]

Hi guys
I just took delivery of my Model 17-6 last week (full-lug, 6" bbl, 6-shot, 1990-91 mfg, see attached pic). Its my first S&W firearm, and the first revolver I've owned since inheriting a non-operational Remington New Model Army .44 back in the 60's. I've had the Model 17 to the range 3 times, run ~200 rds through it, and am pretty pleased with the operation and accuracy so far. I gave it a thorough cleaning over the weekend, and upon inspecting the bore closely noticed that there are some marks that run at right angles to the rifling near the muzzle (see attached pic taken from muzzle end). Can anyone tell me if these are manufacturing marks made during the rifling process, or was the previous owner a bit too heavy handed with the cleaning brush? Should I be concerned about these marks?
Thanks
IslandGuy

 

[islandguy]

p.s. The dark piece of fluff at 9 o'clock in the muzzle pic is a leftover from the last patch I ran through the bore.

 

[Alk8944]

Those are reamer marks and perfectly normal for any barrel with cut rifling. S&W still boraches the .22s, too small for EDM like the larger bores.

 

[pred]

Needs to be shot ALOT more to smooth them out !
Peter

 

[Beemer-mark]

How did it shoot? That's really the deciding factors. I've shot rifles with pits in the barrel that still grouped 2" at 100 yds, which is probably the best they did new.

 

[lebomm]

ALK8944 and Islandguy;
Those are indeed broach marks, but not reamer marks. Since they cross both the lands and grooves, they have to be chatter marks from a broach, since a broach is pulled (or pushed) longitudinally thru the bore. A reamer is rotated within the bore, and produces a cylindrical hole, so it not only can't mark the lands, but it would obliterate them. Marks from reaming the hole prior to broaching would be removed by the passage of the broach, so would not appear in the grooves.
Hope this helps.

Larry

 

[islandguy]

Needs to be shot ALOT more to smooth them out !
Peter

Thanks Pred!
I was considering just giving it a few strokes with the old chainsaw file, but shooting them out would be a lot more fun.
Islandguy

 

[wyatte]

I have a 657-3 41 mag that has those same marks that I got a couple of years ago. Other than that, the gun seems like new. I also wondered what they were from, and whether to be concerned about them. I also figured they might smooth out somewhat with shooting. wyatte

 

[islandguy]

Thanks Larry. Now that I think about it, I have seen similar marks in the barrels of a couple of my older .22 rifles, but those marks didn't appear to be as deep as those in the S&W.
Beemer-mark, the gun appears to be very accurate, except for the odd flyer, which I put down to defective ammunition, shaky hands, and/or failing eyesight. Shooting two-handed, with the butt resting on the shooting bench, its pretty much a tack-driver at 10 yds.
Islandguy

 

[islandguy]

How does it shoot for you Wyatte?
Islandguy

 

[wyatte]

Mine seems to shoot fine - I have not shot this one much though. wyatte