Hello to the forum. I'm here to pick your specialized brains. Hoping someone will have the arcane answer to this mystery.
I picked up the above named carbine at a collector's show.
The lockplate says 1864 and the breech block is the 1864 pattern. The rear sight looks like a Springfield of the era (which coincides with the literature) but not the specific sight used on this carbine.
The breech, barrel and breechblock have matching numbers 158xx. The stock has no visible cartouches or other marks.
Everything I have read indicates that this should be chambered for Spencer .56-52 Centerfire (not rimfire, that was the 1861-2 models).
The 1864 breechblock has the angled channel for a centirfire pin. That pin is actuated by what looks like a modified large rimfire "pin" at the top of the breechblock.
Special note: Someone replaced the centerfire pin with a carefully trimmed finish nail (GRRRRR). I would love to be able to get a correct original or repro pin. It should be the same pin used in the Springfield Joslyn Rifle of 1865.
And, there is what looks like a detent or positioning indent on the bottom of the barrel behind the retention ring, with a wood putty filled hole in the stock at the same point.
The chamber casting is a consistent .66 inch +- .0025 with a length (not including rim) of 2.3 inches.
The muzzle is about .585-587 up to .591-.592 in the grooves. I haven't slugged it because I don't have any lead balls big enough. The diameter at the top of the chamber casting is .594.
Starline 56-50 spec says the rim is .629" to .632" so a 56-50 cartridge can't possibly be a Spencer. Too small, no taper. The 1855 Joslyn had a US Army order for 500 of .58 caliber breech loading percussion carbines. One source I see says fewer than 200 were delivered prior to the war.
The chamber diameter is consistent with several .58 centerfire cartridges of the time but the length is far too long for even a rifle cartridge. I tried a 2-1/2" Magtech brass 24 gauge shell in it. Nearly perfect fit. Just a hint too long to seat properly.
I am totally confused.
I picked up the above named carbine at a collector's show.
The lockplate says 1864 and the breech block is the 1864 pattern. The rear sight looks like a Springfield of the era (which coincides with the literature) but not the specific sight used on this carbine.
The breech, barrel and breechblock have matching numbers 158xx. The stock has no visible cartouches or other marks.
Everything I have read indicates that this should be chambered for Spencer .56-52 Centerfire (not rimfire, that was the 1861-2 models).
The 1864 breechblock has the angled channel for a centirfire pin. That pin is actuated by what looks like a modified large rimfire "pin" at the top of the breechblock.
Special note: Someone replaced the centerfire pin with a carefully trimmed finish nail (GRRRRR). I would love to be able to get a correct original or repro pin. It should be the same pin used in the Springfield Joslyn Rifle of 1865.
And, there is what looks like a detent or positioning indent on the bottom of the barrel behind the retention ring, with a wood putty filled hole in the stock at the same point.
The chamber casting is a consistent .66 inch +- .0025 with a length (not including rim) of 2.3 inches.
The muzzle is about .585-587 up to .591-.592 in the grooves. I haven't slugged it because I don't have any lead balls big enough. The diameter at the top of the chamber casting is .594.
Starline 56-50 spec says the rim is .629" to .632" so a 56-50 cartridge can't possibly be a Spencer. Too small, no taper. The 1855 Joslyn had a US Army order for 500 of .58 caliber breech loading percussion carbines. One source I see says fewer than 200 were delivered prior to the war.
The chamber diameter is consistent with several .58 centerfire cartridges of the time but the length is far too long for even a rifle cartridge. I tried a 2-1/2" Magtech brass 24 gauge shell in it. Nearly perfect fit. Just a hint too long to seat properly.
I am totally confused.