Remington Rolling Block Saddle Ring Carbine Identification Help

[T-Roady]

I recently purchased this rifle and would like to know what it is, etc.
It does not have "Remington Patent" marks on the receiver tang.
The right side of the fore stock is stamped "FCW" and the left side of the stock has a "28" stamped on it.
A "P" is stamped on the right side of the barrel ahead of the barrel band, at the rear of the barrel on the left side, and on the underside ahead of the trigger guard.
The barrel band has a "crown" stamped into the left side.
There is an stock swivel (?) plate on the underside of the stock.
The fore stock retainer spring is on the underside.
The front sight does not appear to be original.
The rear sight, when flipped up, has 3 holes and a notch at the top.
The barrel measures 23 7/16" from the rear of the barrel or 23 5.5/16" from the rear of the receiver.
When closing the breech block the hammer does not go into half cock, but remains at full cock.
After removing the stock, the left side of the receiver tang has a serial number beginning with an "F" and 54XXX, and the left side of the trigger guard plate has a serial number beginning with an "F" and 81XXX.
The chamber measures 1 3/4" deep and the bore measures 0.50+, so I think it is a 50-70 Govt.
I could only attach 3 photos that show the markings and specifics described above. I can show more if needed.
Does anyone have information they can share about this rifle?

[ehull]

At first glance, this appears to be a cut down rifle, as evidenced by the incorrect front sight and the place in the buttstock for a sling swivel plate. The forestock is from a Navy M1867 carbine-- these are readily available for purchase as surplus parts.

[T-Roady]

Thank you for your reply. The lack of the Remington Patent information on the tang confuses me. Is this common or have a reason?
I am attaching photos of the tang, butt stock swivel plate, and the front sight.
Do you have any ideas on the yardage for the rear sights 3 holes and top notch?

IMG_7092.JPG (179.43 KiB) Viewed 2979 times

IMG_7088.JPG (170.67 KiB) Viewed 2979 times

IMG_7082.JPG (182.66 KiB) Viewed 2979 times

[charlielima]

Judging from your picture it looks like your rear sight is a 1963/1964 Springfield Armory rifle musket rear sight. Springfield used these sights on the 1866 Allin 2nd conversion, the 1865 Joslyn, the 1868 Springfield-Remington, & the 1867 Navy Cadet rifle (Remington patent). the only difference I can see is that the Remingtons & the Joslyn only had 1 hole in the sight leave & a notch in the top. My 1866 Allin has 2 holes in the leaf & a notch in the top. The stated ranges for the 2 hole + notch were - bottom hole = 300 yds., the top hole = 500, & the notch on top = 700 (I have an 1866, remainder of info I gathered from 'The .58 and .50 caliber rifles & Carbines of Springfield Armory 1865-1872" Richard A Hosmer author, published by North cape Publications.(Book has pictures)
None of the sights mentioned had 3 holes, but that would not stop anyone changing front sights to drilling another hole. This sight is definitely not a precision device, but a combat expedient item. When my friend remarked about it I told him it was meant to be accurate to "minute of guy on a horse".
Hope this helps you a bit. perhaps it will get attention of someone much more knowledgeable than I am.