Joe:
I forgot to include Schuler's model number, but from Schuler, it is Model 34 noted as "Same finish as above(Model 33), but built especially strong for cartridge 11,2mm with anti-recoil rubber pad." It has a Krupp steel tube part octagon and part round. It was made to administer medicine to pachyderms as per Schuler's catalgues. Original loading was 5g BLP & 30g. bullet. Like Otto Bock, I think Schuler developed the cartridges, but sub-ed the beefed-up designed bolt longarm to Sempert & Krieghoff. This would apply post WWI or after Krieghoff purchased "stuff" from Schilling. Circa 1900, Bock may have made his own.
Kind Regards,
Raimey
rse