Email me a full size in focus close up image of every mark on the barrel flats and just forward of the flats to drewhausemd@yahoo.com
Send as a jpg attachment - not embedded in the email.
Or check this
https://www.shotgunworld.com/threads/belgian-shotgun-identification-guide.232252/ After the proof house revisions of 1924, the
Certificat d’epreuve specified:
“The pressure developed, measured by crusher type device [LUP], lower or equal to 600 kg per square centimeter for sizes 16, 12, 10, 8 & 4; 670 kg per square cm for sizes 20, 24 and smaller.”
600 kg/cm2 = 8534 psi maximum SERVICE pressure;
670 kg/cm2 = 9530 psi maximum SERVICE pressure
+ 10 - 14% by piezoelectric transducer measurement
20g and smaller were PROVED at 1000 kg/cm2 = 14,223 psi or close to 15,500 psi
10g were PROVED at 900 kg/cm2 = 12,801 psi or about 14,000 psi
The
Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives standards were ratified in 1969.