All my hang tag images are 12g and I hope someone can post a 16g or 20g. The pattern % was marked into the late 1930s. Marlin marked the constriction ie. Mod and Full.
Standard loads found on L.C. Smith hang tags: 12 gauge 3 dram 1 1/4 oz. shot (1887 - about 1920 then 3 dram 1 1/8 oz. shot)
16 gauge 2 1/2 dram 1 oz. shot (introduced 1896)
20 gauge 2 1/4 dram 7/8 oz. shot (introduced 1907)