Weird Russian .30-06 ammo

[Jim]

The link below will take you to an ad for Russian made .30-06 ammo. Click "Enlarge photo" and look at the weird groove in the case just above the base. What's up with that?

http://www.cheaperthandirt.com/AMM678-1.html

[gunderwood]

Kind of looks like a belt almost, but if you read the details it points out that it is a brass coated steel case. That groove probably was added to provide some expansion room since brass and steel will not expand at the same rates. That however is a guess as to why they did it and it seems reasonable it has something to do with the metallurgical properties of the two metals being different.

[Jim]

Kind of looks like a belt almost, but if you read the details it points out that it is a brass coated steel case. That groove probably was added to provide some expansion room since brass and steel will not expand at the same rates. That however is a guess as to why they did it and it seems reasonable it has something to do with the metallurgical properties of the two metals being different.

Good guess, G. I have no clue what it's for.

[zephyp]

I would be crious that if you compared the diameter of the part immediately forward of that groove to a "normal" case that you find a slight difference. And, would you also find a difference in the case thicknesses if you compared the "belt" areas. Perhaps when they designed the cartridge they had issues of head separation...just a guess...