Inspector's marks are not reliable for dating a Belgian gun.
PeteM's list shows 'AD' as Alexandre DuPont who was active from 1923 to 1970
http://www.littlegun.be/arme%20belge/artisans%20identifies%20den/a%20dupont%20alexandre%20gb.htm Or it could be the barrel maker who I cannot identify
http://docs.google.com/document/d/17yCstxftvWXpFdSru4JKbRIE1-Q8OqXgJs66tEXntqw/edit The barrels are Twist but carry Smokeless Proof in keeping with the 1927 date. Under no circumstances should the gun be fired without an evaluation by a double gun specialist.
