Cartridge case brinell

[kywoodwrkr]

Does anyone have a link to any information/studies done on the hardness(brinell,rockwell ?) of cartridge case bodies? I have seen one study done on primer pockets to determine if hardness had any influence on blown primers, but nothing which details the hardness of the case elsewhere-ie base, body and neck.
Thanks.

[leftiye]

I'd guess that the primer pocket area of a case would be the same hardness as the rest of the case head. So the hardness numbers from the study should be a good guide to case hardness in general. The head and adjacent part of the case is the critical part that needs to be hard. But, no I don't have any idea as to what hardness a case should be optimally. This in spite of having once explored making cases for sale.

[deltaenterprizes]

What kind of machinery were you planning to use?

[deltaenterprizes]

Does anyone have a link to any information/studies done on the hardness(brinell,rockwell ?) of cartridge case bodies? I have seen one study done on primer pockets to determine if hardness had any influence on blown primers, but nothing which details the hardness of the case elsewhere-ie base, body and neck.
Thanks.

There was a compant making "steel head" cases at one time for higher pressure cartridges. The steel head threaded in to the brass cartridge body.

[kywoodwrkr]

http://www.arl.army.mil/arlreports/2009/ARL-TR-4781.pdf

The above test revolved about the material in the area of the primer pocket to determine if hardening was a contributing factor to loose primers, which could cause jams.
I'm just interested in getting a bit of information about how much the value of hardness of the case increases from the mouth to the base or rim.
The above test was in my opinion too complex, involving polishing of the test pieces. I can EDM the cases and after getting our hardness tester recertified test some materials.
But I still have no idea what the industry standard for cartridge brass is or if there is one.
Once I have this information, then I hope to test some cases exposed to heat and see what effect what temperature for a given duration has on this value.
Not a complex test but I have no base values with out taking standard factory issue brass and testing and using as base values.
I also question whether continued firing of cases cause work hardening in the base area.
Not sure if I'll be able to gather enough preliminary information to even try this.
Thanks.

[holycross]

kywoodwrkr,

This is the first time I've seen testing done using a load. Only seen/ read about testing of cartridge brass by grain size.

Have you read 'COLD WORKING OF BRASS, with special reference to cartridge (70-30) brass' by L.E Gibbs, published by American Society for Metals. Covers brass structure, annealing, cold working, effects of chemical composition, season cracking and testing.

Mark

[kywoodwrkr]

Thanks one and all for feedback.
Here is an earlier test done which does have hardness values over the case length(page 8), although in Vickers values (HV).
http://www.arl.army.mil/arlreports/2004/ARL-TR-3301.pdf
Also found conversion(?) table which may be of some value.
http://www.hardnesstesters.biz/article/008.html
With these my quest may be answered or at least directed.[smilie=2:
Thank you all for your responses.