.45-70 Government. 22" barrel. SN: 42416 (mfg. ca1875). Blued and color casehardened finish, plain walnut stock with short thick wrist and long comb, secured with a single barrel band with stacking swivel. Breechloading single shot metallic cartridge military saddle ring carbine. Breech block marked MODEL/1873/{Eagle Head}/{Crossed Arrows}/US and lock marked U.S./Springfield. No proofs on barrel. Stock with soft and apparently enhanced oval ESA Erskine S. Allin inspector's cartouche and 2/F mark which is also present on the comb forward of the buttplate tang. Circle-P proof behind triggerguard. 1873 pattern ladder rear sight graduated to 400 yards on the base  and 1200 yards on the ladder, with slotted screws. Musket style fixed base and blade front sight. Features include a high arched breech, smooth trigger, two piece triggerguard, and saddle bar and ring opposite the lock. Solid buttplate without trapdoor, however the butt is drilled for cleaning rods. A search of the Springfield Research Service serial number record books did not find this serial number but did find several close to it. #42206, #42242, #42578 and #42552 were all guns issued F troop of the 2nd US Cavalry, consistent with the markings on the stock of this carbine. However, the barrel and receiver of the gun are from an earlier production Model 1873 Carbine and the stock, lock and furniture (with the exception of the solid buttplate) are consistent with a post-1877 production gun. More than likely the parts were married in the 20th century by a collector. The barrel, breech and breech block are certainly late Custer range and could be used in the restoration of an earlier gun or could be made more correct with the addition of a true 1873 rear sight, an early long-wrist, short comb stock with furniture and a correct 1873 dated lock. However, as it sits it is a good representative example of an "upgraded" Model 1873 to 1877 carbine.