.58 caliber. 33" round barrel secured by two flat brass spring-retained clamping bands. SN: 1499. Browned barrel, color casehardened lock, brass furniture, smooth walnut stock. Muzzleloading percussion rifle modified by Colt. Lock marked REMINGTON'S/HERKIMER/N.Y. in three horizontal lines under the bolster and in two vertical lines at the tail US/1849. Breech plug tang dated 1851 with the upper left quadrant of the breech stamped with US/JCB/P inspections. The counterpane opposite the lock is stamped with two crisp script cartouches, the SK of arsenal sub-inspector Samuel Knous and the WAT of Ordnance Officer William Anderson Thornton. Colt installed Saber bayonet adapter ring numbered 1499 with the bottom of the barrel numbered to match. Rifle retains the original brass blade front sight, the Colt added rear flip up leaf rear sight, both sling swivels and an original full-length trumpet-head brass tipped ramrod with good threads. This rifle is one of the 10,411 purchased by Colt from the US Ordnance Department in 1861 for $10 each and which he subsequently resold to them for $18.50 each. The "alterations" that Colt performed were to rebore the rifles to .58 from their original .54 caliber configuration, and although he had offered to re-rifle them, few extant examples show the 3-groove rifling that Colt would have used, but rather nearly all retain the original 7-groove rifling from their .54 caliber round ball original manufacture, as does this one. Colt also equipped the guns with the three-leaf sight that was used on his Model 1855 Revolving Carbines and added a muzzle ring with bayonet lug to accept a brass handled saber bayonet. The rings and the bottoms of the barrels were both numbered to match when the alterations took place. As the Mississippi Rifle was produced on the principle of interchangeable parts, barrels were often swapped from their original host guns and installed in other guns, as the barrel was the part that had to be removed and machined as part of the upgrade process. These rifles were issued to a variety of US military units during the early days of the American Civil War and while they survive in reasonably good numbers for collectors to acquire today, rarely do they appear for sale in such nice condition or with matching numbers on the bayonet ring and barrel. The rifle retains an original period white buff leather sling with an illegible maker's and inspector's mark. {ANTIQUE}