My current 6.5 Carcano ammo types
6.5 Italian issue head stamped SMI 952 (came in a clip stamped SMI 952)
6.5 Carcano military clone ammo (160gr FMJ from obsolete ammo vendor)
Both of the above have an odd depressed ring in the cartridge head
.264" 140gr spire point (from my crappy reloads, Norma brass)
.268" 160gr round nose (from my crappy handloads, Graf brass for .268")
MY observations
_ The Italian SMI 952 bullets, like the hundreds of pulled Italian military bullets I have used over the years, are somewhere between .264" and .268" in diameter. Same with the clone ammo.
_ Reload Norma cases with .264" bullets only, cramming a .268" bullet in the thicker Norma case neck, not a good idea.
_ Reload Graf cases with .268" bullets only, a .264" bullet will be a loose fit in the thinner Graf case neck.
_ I see no difference in accuracy between .264" 160gr bullet in Norma cases and .268" 160gr bullet in Graf cases in my 1940 made Carcano.
_ My results with bullets lighter than 140gr have been bad. My best results have been with 160gr bullets.