I had an 1889 before, and i had the same problem.
It's a carrier issue.
The carrier is not coming up and stopping the next round.
Usually, this can be fixed if a smith can tig weld and build
up the bottom where it is worn.
Finding a new one or new old stock in this case will
likely be difficult.
I have seen people shim the bottom of a carrier before
and there have been threads about it here on this site.
Using JBWeld and a piece of a hacksaw blade.
Sounds like a Bubba job but it works.
I hope you get it running.