Spencer Carbine with an Octagon Barrel

[Sedalia Dave]

Wonder when this conversion was done.

https://www.gunbroker.com/Item/974112949

[Trailrider]

Could have been about anytime after the Civil War! Lots of them were surplus, and sold off to civilian trade. About any good gunsmith could have made the changeout. What cartridge it might have been chambered for would have depended on whether the owner wanted to keep it a repeater, or single shot with a longer cartridge.

[El Supremo]

Thanks for the alert:

It appears to be in great external condition.  Wood not damaged in the usual places.

Trailrider:
This is the first I have heard of the possibility of chambering for a ctg longer than will cycle.  Makes sense that it could be, but can anyone please share about this? 
Many thanks.
El Supremo/Kevin Tinny

[Big Goose]

  For original rimfires, one would only need to ream the chamber deep enough for the 50-60 Joslyn ( 1.6 inches I think) , could single load the 50-60 Joslyn and still have 56-50s in the magazine.( works great in 1865 models with the Stabler cutoff)  For centerfire conversions, could do the same... 50-70 is a bit too long without significantly  modifying the cartridge follower , but 50-60 Joslyn will load fine...  the 450 grain boolet over 60 grains of 2 f Olde Eynesford is a real buffalo killer.   

[Sedalia Dave]

My 1871 Springfield Armory Spencer Conversion will chamber brass up to 1.6" long. If I were to single load it the action will accommodate a cartridge with an OAL of at least 1.95". It might chamber one longer but this was the longest dummy cartridge I tried.

However it will not cycle any cartridge with an OAL greater than 1.6"

50-90 Sharps brass fits the chamber the best so I cut the brass back to 1.3". I am using a modified Accurate Molds 51-330S to cast my bullets. I had the crimp groove eliminated and deepened and widened the lube groove to ensure I have enough lube for the rifle length barrel. 

[El Supremo]

Thanks, guys:

Very helpful.

I had forgotten about the longer chamber in the 1871 version, and was a bit shy about using a more potent ctg. In originals.

All the best.
El Supremo/Kevin Tinny

[Jack Wagon]

These mountain rifle conversions are very interesting. My unmarked conversion fires a .48 cal bottleneck cartridge which run through the magazine.  My centerfire cartridge  easily holds 45 grains of 1 1/2 Swiss. It was built from a new model carbine with the Spencer cut off and  single set trigger. It has been said that Liver Eatin' Johnson carried a Spencer conversion when he was a wolfer and woodhawk up on the Musselshell.  Centerfire 56-46 on the left and 56-48 on the right.  Jw

[Jack Wagon]

56-46 centerfire on left and 56-48   Jw

[El Supremo]

Thanks, Jackwagon:
Impressive stuff.  That load must be a zipper.  Any idea of its velocity, please? If not, perhaps the added drop from 50 yds to 100 yds?
Most of my std case 56-50's w full case of 3F Swiss and a 320 gr bullet avg around 7" of drop between 50 and 100.
Big smiles and likes.
El.Supremo/Kevin Tinny

[Jack Wagon]

Sorry Kevin, I don't have a chronograph. My backyard range is only 50 yards, so I don't have that information either. The 56-48 takes 15 grains more powder than my 56-46 and shoots a 300 gr bullet instead of a 270 gr. It is quite a bit more impressive that the 56-46!  Jw

[El Supremo]

Thanks, Jack Wagon:
The drop from 50 to 100 will tell me enough if you have that figure, please.
Just trying to roughly compare performance of mine vs your hotter round via drop.
My shooting buddy is not interested in duplicating either Davy's or Joe Izuzu's catching bullets in their teeth when aimed at the apple.  Haha. Those are classics.
El Supremo/Kevin Tinny