An original Yugoslavian made M1919 8X57 barrel is a good find. I have a M1919 semi-auto in 8MM that was build from a part set that came out of Yugoslavia. We thought it was 30-06. The mods to the feed made me check the barrel and discover it was different. Lots of Yugo arsenal proofs on the internals. I had hoped that the Vol. II of Goldsmith's Browning book would have given some idea how many of these exist.