Thread: 900kg proof mark

I have an aya side by side and the proof mark is 900kg. Any one know what that would equate to in the old school? 1 1/4 oz? 1 1/8oz?
She is a 12 gauge 70mm chamber

I wouldnt stress about it... there are heaps of older SxSs out there still going strong.... the really tight older shotguns do pattern better with the lighter loads all the same.

Thats not the charge weight thats the proof pressure. 70 mm is the shell length 2 3/4. Top charge would be 1 1/4 LEAD shot but start on 1oz trap loads first if youve not used one before. There should be a couple of stars stamped on the barrels too. 1 is full choke, 5 is cylinder. Its common to have one barrel full one half choke or 3/4 1/4