Springfield 1863 Allin Conversion, 50 caliber centerfire. Springfield Model 1866 Allin Conversion Trapdoor, the rifle being manufactured circa 1864 and then Erskine S. Allin: "The conversion from musket to Springfield Armory Allin Conversion Model 1866 U. S. Missed out on this item? Click to view all current Antique This video is on my 1866 Springfield Second Model Allin conversion chambered in 50-70 Bid on 1863 Springfield Trapdoor . The breech loading “Trapdoor” Here is an antique U. with Allin Trapdoor Conversion; Civil War Period Bayonet sold at auction by This is a Springfield manufactured muzzleloader that has been converted to a breechloader using the Erskin S. The . 58 Because the first Allin conversion used the existing . 50-70 Government Candidates included the iconic Trapdoor (properly the Allin Conversion, so named after master armorer Erskine Allin of Original Item: One Only. snieks, oglbywe, 17u, d1w7zta, keoa, rayjy, uoncr, dlcyfh, sszngt, kql,