Stealth Brass

i “know” some FN and SB from spain who made rounds without headstamp

There is plenty of unheadstamped cases around from a variety of manufacturers.
In particular nowadays where they are using pre-produced “blanks” and only later apply the headstamp by laser.

Well, not to further muddy the waters, but I have some 7.62x51 with MAL headstamps that also have a three point primer crimp, but they are more of the ‘punch’ style rather than the ‘bar’ style.

The crimp is very similar to the “norma 223 REM” crimp, and looks like the same style of head:
223 Rem Norma crimp primer once fired brass reloading cartridge cases. Pin  polished(100 CT.
image source: google

With Norma I asee RUAG coming into the game and there I also saw un-headstamped cases.