Seeking an antique Russian ammo expert

I am translating a Ukrainian (but written in Russian) article about 7.62x54R history, the one Jon found on internet. I need to consult an expert about cartridge construction of 4.2 Line Berdan (10.75x58 mm) as it is discussed in the article. I’ll be at SLICS (in The Hotel) on Tuesday. May anyone suggest a knowledgable person who’ll be in St. Louis? Also, I’ll be looking for a proof reader when I struggle through the entire thing. Thanks aforehand.

Vlad: Speaking generally, Russian-made Berdan cartridges follow the original UMC design closely; UMC may very well have provided tooling or at least made suggestions in this area. The typical .42 Berdan cartridge of Russian manufacture is very similar to a .43 Spanish Remington of UMC or Spanish military production. This is not to say you should drop the idea of finding someone at SLICS but will give you some idea of what questions to ask. Jack

Lots of mystery surrounding the .42 Russian including blue , orange , black and red paper patches. A recent police book from the Ukraine IDed the blue one as a carbine load. Who knows ?

The blue patch is the Gatling MG cartridge and the red (pink) one is for carbines.

I had always heard of the blue paper patched round as being for the Gatling gun.
M. Rea