I believe Beinke and Beinke can re-line that caliber. It was introduced around 1900. It was a highly respected target round in its day. It was chambered in the 44 and 44-1/2. Remington loaded it from 1900 to 1918 with a 120 grain bullet and 30 grains of Fg.
Maj. Ned Roberts wrote quite a bit about his love for a .28-30 single shot he once owned in one of his books. I believe it was his book on Schuetzen Rifles. It's a great caliber, and definitely not one you see every day. I have Stevens singles in .25-20SS, .25-21, .32-20, and .44-40, but like kell, I'd love to own a .28-30!
I was looking at CPA's catalog when I first found out about it I since was given about a dozen old gunbooks and this caliber gets mentioned quite a bit. I also have a copy of Robert's book on Schuetzen's and read his part on the 28-30.