Below are a couple lineups of 9x19 proof cartridges, or at least what are purported to be proof loads according to the notes with them. I recognize the R-P and W-W cartridges, and have seen a couple others, but many of these, especially the unremarkable looking IVI loads are unknown to me. The blackened (steel?) case IVI load is interesting, as well as the Swedish ones which have notes referencing them as being export proofs for Denmark.
Matt, those two Argentine cartridges by FM San Francisco that bear no apparent identification would have been taken from boxes labeled proof. Do you know the origin of these rounds?
The IVI loads look to have copper-washed cases. This was the old British method of identifying proof loads.
I don’t recognize the red base R-P load on the extreme left as a proof, for two reasons, I’d think the case should be tinned show a red tipped bullet from this era (see the one to it’s right - SAAMI rules) & the base color doesn’t look right. Probably John or Lew will have more to offer, but that’s my 2¢, or less.
Falcon is correct about the copper-wash ID. The Swiss also did that.