Потому и запостил вопрос, что очень похожа гильза на заведомо китайскую 7,62х39. С подачи Costas нашел такую цитату:
If Your ammo has copper washed steel cases it is NOT Belgium "FN" manufacture. It very well may be be Chinese manufactured 30/06.
The Chicoms made a number of Identical head stamp ammunition calibers that were imported here a number of years ago. I've seen "LC52" head stamped .30 Carbine that has steel copper washed cases and is Chinese manufacture and corrosive primed. I have two ammo cans of 7.62 NATO that is head stamped "RG 1960" with the NATO cross. The ammo is a Chinese made exact head stamp copy of british "Radway Green" 7.62 NATO ammunition. The ammo has steel copper washed cases and is corrosive primed. The Chinese "LC52".30 Carbine and the "RG" 7.62X51 ammo is well documented.
All of the real "FN" 30/06 Military ammo I've had (and I've shot a lot of it in the 1970's) in the past were all brass cased, no steel cases. I suspect your 30/06 is a Chinese forgery and is corrosive primed.