Sergei Aleksandrovich Buturlin (1872-1938) was a Russian Ornithologist who also published extensively on hunting and sporting arms, including
Drobovoe Ruzhże IstrelżBa Iz Nego (The Shotgun and Shooting It) in 1929. No English version of the several editions exists.
Robertovich graciously translated his 1938 edition
http://rutracker.org/forum/viewtopic.php?t=3524270The original
I had to screen shot the chart from the Word doc as it didn't format to the Forum from my website
One analysis showed Krupp
Spezial to have .61% carbon