Springfield made the Model of 1905 rifle bayonet which was affixed to various rifles in early in the 20th century through WWI, WWII & the Korean War. It was initially developed for the US .30 caliber rifle 1903, aka, the Springfield Model of 1903 and first saw action in the Philippine-American War of 1899 - 1902. The designation "Model of" was shortened to "M" in 1925 when the US Army adopted the "M" nomenclature.
I suspect the medallion was part of the M1905 bayonet commemorative package endorsed by the NRA. It may have also been part of a NRA commemorative package featuring the Springfield M1903 with the M1905 bayonet.
It was not unusual for the NRA to endorse commemorative editions of firearms and firearm accessories (Google NRA Commemorative) back in the day and they still do it to this day.
eBay price for the medallion runs about $15 - $20