1873 - Wikipedia
Colt Single Action Army - Wikipedia
Model 1873 Springfield First Type Officer's Sporting Rifle, 45-70 Caliber Serial Number 45 (Total quantity 477) One of small group bearing 1881 inspectors' mark A superior early production example; subsequently became the US Model 1875. All model 1873's manufactured after serial number 525923 are considered modern and are subject to all the BATF Federal guide lines including back ground checks. There were over 720,000 Model 1873 Winchester 's manufactured. The longest barrel length known on a Model 1873 is 37 inches.