.308 with cuts running parallel

[ozone]

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I was as range today and picked up at least 50 used .308 cases and everyone had exactly the same cuts running parallel from the open end back about half the cases length.

I wondered what could do this? There were many more that I did not pick up as I walked back and forth to the target from the firing point. They were everywhere in groups of 10 to 15 so the person using the rifle was using the entire range or more than one person was firing similar rifles.

Anyway every single case had exactly the same cuts that were deep and sharp enough to see and feel. The cases had only ever been fired once so I imagine the scoring happened as the thing was fired inside the chamber, on inspection one or two others suggested that it was a poorly fitting case in the chamber but it stuck me as quite odd.

So what could cause multiple parallel scorings very close together and all the way back half way up the case?

ozone

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[Anaxes]

Like this? Fired in a fluted chamber.

[No i deer]

Used in a machine gun I expect.

[Chris-NZ]

From an H&K probably?

[ozone]

14 hours ago, Anaxes said:

Like this? Fired in a fluted chamber.

Yes almost identical

9 hours ago, No i deer said:

Used in a machine gun I expect.

That is what another said

8 hours ago, Chris-NZ said:

From an H&K probably?

And that is what somebody also said.

Thank you cheers guys that makes sense knowing what the range is used for weekdays.

Regards ozone

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