Lew - I had forgotten about the Bulgarian 9 mm rounds with no headstamps. I have two of them. One from c.1946, and one from either late in that year or after. In 1946 or 1947, Kazanluk changed the width of the extractor groove and bevel on 9 mm, and I have unheadstamped rounds with both the early style and the later-style groove and bevel.
In context, I would now agree that the round Ivo has is probably Bulgarian. The Swedish ones are somewhat scarce and not likely to have been found in Bulgaria.
Still, it is good when posting to give the best information you can. IN the case of the Swedish round, aside from ogive of the bullet which is hard to “read” in photos, and sometimes even distorted, the primer is that large primer cup that Sweden used in so much of their pistol ammunition, 9 mm Para and 9 mm Browning long, which is why I requested that measurement. Of course I asked for weight of the round
for the very reason you mentioned. While your posting is a little confusing, I assume that on the last description of the paragraph, you are talking about the Swedish round, with a blunter bullet and heaveier
overall cartridge weight.
At any rate, good ID! I should look at my 9 mm rounds more often and remind myself of what I have in
my own collection.