Choke 17.5mm = .689", 18.3mm .713""
17.5/25.4=.689" ;; 18.3/25.4=.720", might want to double check your math on that 18.3 dimension.
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The 89.5 grains of powder would have been Black Powder & equals to about 3¼ drams, so the gun was proofed for a 3¼-1¼ load @ then current pressure levels, as stated not todays SAAMI standard. "IF" in proper condition the load you mention should fall within those parameters.
Miller,
Well, I ran it again. Of course you are right! That is what I get for posting at 2am. You are also correct that Black Powder should be assumed. The smokeless loads of that day simply do not equate to modern smokeless.
jigman48,
I would assume at this point that if you sneeze through those barrels they will turn to dust and the stock will become a pile of oil soaked splinters.
The point is that gun has to be examined in person by a competent gunsmith, as others have said. I purchased a perfectly good gun about the same age. I had it examined. Upon disassembly a crack was found in the receiver. Would the next shot have destroyed? I did not want to know, so I paid to have it welded. You can not judge what you can not see.
Pete
