70 mm (2 3/4") chambers
20.6 = .811" is chamber (not bore) diameter
18.3 = .720"
17.5 = .689"
Gotta know the bore, but if it's .729 that would be IC and Full-nice chokes for about anything.
And yes, I'd certainly limit to 1 1/8 oz loads.

And here's infro about Neumann Freres with pics of their trade marks

http://www.littlegun.be/arme%20belge/artisans%20identifies%20m%20o/a%20neumann%20freres%20gb.htm

Last edited by revdocdrew; 08/24/07 04:57 PM.