Today this projectile came in from a French auctionsite (delcampe), and was described as an experimental French projectile…
I was told by a BOCN member that the projectile should belong to a 20x139 round.
It came in a (fired and ‘re-‘crimped) 20x110 case, and I wasn’t sure of anything on this particular projectile, so I did compare the ‘bleu tipped’ projectile to a 20x139 and a 20x110RB projectile, and the crimping grooves didn’t match neither!
When compared to a 20x102 projectile, the crimping grooves are spot on.
So my guess is that it is in fact a 20x102 projectile
Someone draws a different conclusion ? (or has some original documentation about it ?)