Hello all (1st post)! I'm considering buying what I think is a 1911 Sauer and "son" SxS 20 gauge made for US import and I have a couple questions I hope you guys can help me with. My only knowledge of this stuff is from decoding the proof marks on my 1955 Sauer and Sohn 12 gauge and what I read on forums like this one so I may be wrong in my assumptions below (and above).
Q #1) can I shoot light target #8 modern shells through it (assuming chamber is 2 3/4")? It has no "nitro" or "eagle over N" proof marks but reading old threads here it seems this time period had only voluntary proof marks for smokeless powder and it was inconsistently (perhaps rarely?) used.
Q #2) What does the "19" next to the 20 inside a circle proof mark mean? I have seen things like "13/1" next to circle 12 which I understand to mean the specific bore diameter but have not seen one like this where the number to the left of the circled number is less than the circled number.
Q #3) any indications on the proof marks shown that it is 2 3/4" chambers? I assume it is 2 9/16" which I understand is common for this time period?
Here are some proof mark photos that might help (these r all the pics I have with proof marks): I apologize for links showing up instead of pics, not sure how to embed pics yet.
https://imgur.com/90Ss2U0https://imgur.com/GC3hhIS https://imgur.com/j8vjVY8
