This is a 5th Model Burnside Carbine in .54 cal percussion. Nice gun w/ matching numbers that's complete with original sights and saddle bar. Designed in the 1850's by Ambrose E. Burnside who was soon to become a Union general during the Civil War, his carbine was widely issued to Union Cavalry regiments throughout the war. Flayderman's Guide mentions several Cav units issued these carbines including the 1st Michigan; 3rd Indiana; 5th, 6th, & 7th Ohio; 1st NJ; 3rd WV; 3rd, 14th, & 18th PA; and 2nd, 12th, 14th & 16th Illinois.
Overall condition grades to NRA Antique Very Good+ with a very pleasing overall appearance. Strong original blue remains on the lever and loading block. The case colors on the frame, lockplate, and hammer have mostly worn to a nickel-silver appearance. Nice markings throughout. Barrel is a light gray that's beginning to haze over to a light brown patina. Several screws still have much of their original blue remaining. Very Good wood that's never been sanded or cleaned...great wood-to-metal fit. Nice grain with a few handling markings but no chips, cracks, or repairs. US military inspector's cartouche located on the left wrist of the buttstock. The action is in excellent condition...just look at all the original finish present inside the breech area (see photos). Bore is dirty and needs a good cleaning with a large brush. It should clean to at least Fine and more than likely Excellent as the rifling is sharp and original blue is still inside the chamber. In my opnion, while it shows light, mostly external use, it doesn't appear to have seen more than a few months of actual service. A nice example of a Civil War breech loader.