04-09-2023, 06:11 PM
jkucukov Wrote:I looked at it again just now, it seems the 2 out of 6 lands in the throat area don't extend all the way down to the case mouth. Its a gradual taper from the rifling down to the edge of the case mouth line. It seems the chamber might not be concentric with the bore (ever so slightly off).
Here is another picture showing a gouge on one of the lands right above the case mouth edge.
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Picture #2 compared to Pictures #1 and #3, are the tell that it's an uneven concentricity. This is WAY more common than people think. The reality in my own experience is there are two places that matter in a barrel, the throat, and the crown. In between basically doesn't hardly matter at all. It's why a pitted and corroded barrel, or a barrel damaged by fugitive steel media, can still shoot lights-out. So long as the throat is well uniform, and the crown is good; that barrel will still shoot.
And that barrel - is not.
You have to be careful with optical illusions and dirty aspects misleading you to think mis-machined. So run a few dry patches and reimage, just to be sure. But from what I'm seeing, that is not a square and concentric chamber. Meaning every single shot is starting its journey crooked, within the first 1/2" of its travels.
4x P100