On top just behind the trapdoor opening. 4 to 6 numbers probably.
Your springfield model 1873 trapdoor was made at springfield armory in the year 1883.
your trapdoor was made in 1874
With the serial number that you provided,your Springfield Trapdoor Model was made in the year 1884.
With the serial number that you supplied,your Springfield model 1873 Trapdoor rifle was made in the year 1884.
about 1890
With the serial number that you provided,your Springfield model 1873 trapdoor model rifle was produced in the year 1875.
With the serial number that you provided,your Springfield model 1873 Trapdoor Carbine was produced in the year 1877.
made in 1875
your trapdoor was manufactured in 1880
Your trapdoor 45/70 was made in 1880.
your trapdoor was made in 1881. there is seldom any history unless obtained from owners family who would know much about the gun and owner.
With the serial number that you have supplied,your Springfield model 1873 rifle was made in the year 1874.