Brass head imprinting: what made this?

[sthwestvictoria]

I have been a gifted a job lot of .243 reloads. I am in the process of pulling them and dumping the powder and primer as they will not chamber in my model 70, likely having been neck sized only.

About 90% would be Winchester headstamped. There are some Norma and then these fellows with only the calibre and this odd herringbone imprint on the brass of the headstamp.

http://castboolits.gunloads.com/imagehosting/thum_209934f8ebb11a784b.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=4850)

Is this a bolt imprint? some type of reloading ram?
This is in Australia but these rounds are old and so could have been used in the 1980s before the semi-automatic buy-back. I have range brass with fluted sides and dinged necks which I believe comes from some semi-autos, particulary the FAL but haven't seen this imprinting.

I'll recycle them.

[Bret4207]

Huh, never saw that before. To me it looks like almost like a stress reaction from forming. Might be interesting to section a couple and see what they look like inside. Are the primer pockets loose at all?

[stubshaft]

Definitely an odd duck.

[frkelly74]

I think it might be imprinting from the jaws of a vice. I had similar marks from using one of the lyman sizing dies to size some brass. I lubed cases and forced them into the die with my bench vice, not knowing about arbor presses at the time.(From back in my lee loader days)

[geargnasher]

It's probably brass someone reformed from 7.62 NATO, and were kind enough to file the headstamp and redo the numbers. The primer pocket may have been re-reamed, check it's depth vs. spec to see.

Gear

[montana_charlie]

It might be one of those 'non slip' patterns found on some types of steel plate.
A piece of such plate may have been used for the 'anvil' when driving out crimped primers, prior to making the current reloads.

Is there any reason to believe the original primers may have been crimped in?

CM

[sthwestvictoria]

Vice marks probably do make sense.

Simplex, an Australian die and press manufacturer, does or did make sizing dies to use in a standard workshop vice:

http://westernfirearms.com.au/reloading-reloading-dies-die-a-rama-303-270-fl-simplex-vicecase-forming-die-p-2202.html

So that sort of imprinting probably arose then.