Here is a link to some info. These guys at Doublegunshop.com know their stuff.
http://www.doublegunshop.com/forums...=1&PHPSESSID=3017ca4a2ca64d34c6f1ef395c9b7c75
If it says union firearms co. then it is before 1910. If it is after 1910 it would read Union arms co.
http://www.doublegunshop.com/forums...=1&PHPSESSID=3017ca4a2ca64d34c6f1ef395c9b7c75
If it says union firearms co. then it is before 1910. If it is after 1910 it would read Union arms co.