The 16/C in the Diamond simply denotes it is chambered for a 16ga shell without actually specifying the length. This gun was proofed in the era where all guns receiving a Nitro proof had to have chamber length & diameter specified. As Pete stated this is 75mm (2.953") long or essentially a 3" chamber. The diameter was measured at the largest point or just inside the rim seat. The 18.9mm converts to .744" which is well within the range for a 16ga chamber. It would taper down some .015" to the forward end just ahead of the forcing cone. This situation fits the 1898-1924 date range Pete stated.
I consider myself to be somewhat cognizant of Belgian marks or I can look them up in a text or Pete's site. But Peter & 2-piper might need to knock the dust off of their monocle and have a closer gander the ensemble of marks as I'm 110% certain that the subject sporting weapon passed thru a German proof house & I'm nearly that certain that it was Z-M. I challenge any and all to prove otherwise.
German touchmarks noting proof in the final state more than likely at the Z-M facility.
Crown over W - constriction
Encirced 16, etc. - bore
Date & ledger number which are almost illegible but an 8 is visible in the date-code.
Kind Regards,
Raimey
rse
