Sorry for not paying attention
The ‘LLH’ of
Laurent Lochet-Habran has been found on Fox, Baker, Lefever, Crescent, Ithaca (Lewis & Flues with ‘Smokeless Powder Steel’), NID, Lefever Nitro Special, Lefever M-2 single barrel, and Westernfield Deluxe/Western Arms Long Range, Smith
Royal, Armor, London, Crown and Nitro barrels and Hunter Arms Fulton and “Ranger” for Sears. Baker guns may be marked “Nitro Rolled Steel” and Folsom Crescent guns “Fluid Temper Steel”.
1912 F grade with Royal Steel, LLH and ACL (Acier Cockerill Liege)
I haven't tested a Royal steel segment, but it very likely compares to other tubes manufactured by
Laurent Lochet-Habran Walt Snyder documented a report from 1919 that an unknown Ithaca barrel was AISI 1030 with a tensile strength of "about 70,000"
A c.1925 Crescent Fire Arms “Genuine Armory Steel” with ‘LLH’ mark was Rephosphorized AISI 1040 Low Alloy Carbon Steel with a tensile strength of 104,000 psi
104,000 psi tensile strength is similar to 4140 gun barrel steel, but obviously with less corrosion resistance and is likely softer.