Not relevant to 1909, but of interest

The Mechanical and Other Properties of Iron and Steel in Connection with Their Chemical Composition, 1891
https://books.google.com/books?id=-c8xAAAAMAAJ&pg=PA30&dq
For ordnance material generally a harder and stronger kind of steel is used, although some prefer a mild steel for guns:
Terre Noire: .12% carbon;
Cammell: .14 - .19%;
Vickers: .24 - .27%;
Trubia (Spain): .23 - .33%.
Harder steels:
Firth: .34 - .4% carbon;
Whitworth: .3 - .42%;
Bofors (“Open hearth” cast without blowholes): .35 - .45%;
Witten: .47%;
Krupp: .45 - .71%;
Terre Noire (“Open hearth” cast without blowholes): .5 - .88%.

Barrels for small arms carbon content:
Solingen .13%
Terre Noire .3%
Spanish .43%
Witten .47%
St. Chamond .49%
Firminy .57%
Unieux .60%

Manganese
Five samples from Krupp guns average .14%;
Firth, Whitworth, Cammell, Vickers gun steel averaged .23%;
Terre Noire forged steel .2%;
Witten .41%;
Bofors steel .35 - .60%;
Terre Noire steel .53 - .67%.

“Gun Steels”
https://books.google.com/books?id=-c8xAAAAMAAJ&pg=PA196&dq

Krupp Fluss Stahl (Homogeneous Fluid Steel) was introduced about 1890 and by reported composition was similar to AISI 1045.

Krupp Spezial Gewehr Lauf Stahl (Special Gun Barrel Steel) was similar to AISI 1060.

Krupp marked tubes stamped “Acier Cockerill” or with “LLH” of Laurent Lochet-Habran are commonly found.

American Rifleman, April 8, 1915, Fred Adolph, “More About Gun Barrel Steel”
https://books.google.com/books?id=EpcwAQAAMAAJ&pg=PA25&lpg
“Krupp makes 200 kinds of steels”


BTW: Composition analysis by Optical Emission Spectroscopy is quite precise
https://docs.google.com/document/d/1dnRLZgcuHfx7uFOHvHCUGnGFiLiset-DTTEK8OtPYVA/edit

https://sites.google.com/a/damascusknowledge.com/www/home