ID buffington rear

[emmagee1917]

Gentlemen ,
First post in this sub-forum as I'm more into WW2 firearms. I have a rear sight I'd like to place in the for sale forum , but I need help ID-ing it and it's rifle.
It is a buffington style rear for sure. It is pretty close to the first pictures on Frasca's site in the buffington thread below . The difference is that it is stamped "C" in the upper corner where those in Frasca's site are " R " and "XC" . The markings are on the right ladder arm and go from "2 " up to "19" in 100 yrd jumps . On the bottom of the left arm , below what I would call the battle sight , is a "19 " and a "20" mark , but I can't see how they'd be used.
Is this a trapdoor or krag sight ? Which model rifle ?
Thanks for any assistance you can give and I'll post it down in the for sale after I ID it and take pictures.
Chris

[Dick Hosmer]

You have a regular carbine ("C") sight. The "XC" sights were for a special 24" barrel variation. It is definitely trapdoor, not Krag. The amount of elevation required is so great at extreme range that the UPPER peep is used when the arrows are aligned with the highest graduations. The lower peep is used for short to moderate ranges.

[emmagee1917]

Thanks for the reply . Is there a specific model it fits ?
Thanks , Chris

[emmagee1917]

Ah , I think I get it now. The lower peep and " tree" is used with the right arm markings and the upper peep is used with the left arm markings but using the line from the lower peep to do so.
Thanks , Chris.