I have one originally produced in 45/70 built in November 1886 according to the Cody museum,
serial number 1001 the early models have a locking stud on the lever
It now has a 28 inch badger barrel in 50 /110 express and an original tang peep sight
when I first saw this rifle in Wisconsin some 20 years ago it was a real junker. the barrel was half octagonal to round with express sights. found neglected and unloved in the corner of a Canadian gun shop.
I have a NEI mold which throws a 300 grain gas check bullet using lynotype
According to cartridges of the world the 300 gr express bullet should travel at 1600 fps
I got a surprise when I put it over the chrony and got 1960 fps consistently using 110 grns of Goex cartridge ,no sign of excess pressure at all
I have alot of fun shooting this rifle