This looks to have been in storage for many years and really doesn't need much more than a good cleaning and wipe down. Bore is very nice with dust and some spots of surface oxidation. There are several 44-70 loadings by Rem, Ballard and Sharps so I will do a chamber cast. A 45-70 lead drops through so I expect it is in the 475--52 series. 

Not sure those are vise marks on the barrel? I believe that's the side of the barrel covered by the forearm, and not usually finished.

67/49 indicates a .410 bore before rifling. A popular cartridge in this size was the 10.3x65R which happens to be the same size as a 2 1/2 inch 410 shotshell. You might try a 410 in the chamber just to see if it is a snug fit indicating the possible 10.3x65R. Don't shoot it! However, if a .457 slug drops down the barrel then something drastic has changed since it was made and all bets are off. Sounds like a chamber cast is in order.

Thanks guys for the replys.  I will have to do a cerrosafe cast and see what it is.  A .410 2.5 inch shell is a sloppy fit to about 1/4" where it hits the throat. It very well could be a 44/77. I am also having the same fits with a 67 Navy Barrel on a type 1 1/2 carbine receiver. The last owner said he  was told it was in 56/50 CF. That would make it a very rare piece.  If anyone has any ideas on the possible maker of this by id'ing the action or whatever please let me know.  All comments are welcom.