The Hunter Arms Fulton patent dates to 1911, and the gun was introduced in 1915. The 'Standard Load' found on L.C. Smith hang tags 1887-1930 for 12 gauge was 3 dram 1 1/4 oz. until about 1920, then 3 dram 1 1/8 oz. The SuperX 3 3/4 dram 1 1/4 oz load was not introduced until 1922. You decide keeping in mind the stock wood of your gun is now almost 70 years old.