Rifle measures 47” overall with a 30” round barrel that features six-groove rifling. 52 caliber rimfire longarm that used the “No. This specimen, serial #1646, was one of the approximately 11,000 produced between 18. Initial army contracts with the Spencer Company of Boston, Massachusetts called for 10,000 repeating firearms at a cost of $40.00 each. This famous longarm is a Civil War Model 1860 Spencer Repeating rifle in very good original condition.