M&P 40 Rifling Defect?

[dpc]

I purchased my first M&P recently which seems to have an unusual rifling pattern (see attached pics)

Its essentially a pinstripe pattern with every second "stripe" having multiple cuts in the stripe running perpendicular to the barrel. These cuts run the length of the barrel but become more frequent the closer you get to the muzzle. These cuts appear to be of different depths and widths. The camera doesn't do it justice, there are easily a dozen cuts per stripe. The in between stripes are smooth, i.e. no cuts.

Ive never seen a rifling pattern like this, is this unique to M&P or is it a defect?

Thanks

[TRUE MP]

SEND THE PICTURES S/W CUSTOMER SERVICE

[Jyezahn]

Your barrel should not look like that. Contact S&W.

[Robotech]

Looks like the CNC boring tool was failing, and it's severe enough that they should have caught it!

If they missed this one there may be more out there. Definitely report it, and you might want to post your test-fire date so others here with about the same date of manufacture can check theirs as well.

[MichiganScott]

Reamer marks from boring the hole prior to rifling. I've seen rifles like that. Copper fouling built up to the point that cleaning every 15 rounds was necessary.

[dpc]

Test fire date on the casing supplied with the pistol 07-09-2012.

Thanks for the responses. I've contacted S&W, i'll let you know how it plays out.