Reloading questions for 0.50 Rimfire Remington Rolling Block Carbine

[Patrick Chadwick]

Seems to be a Style I (Layman's usage) Whitney** RB rifle in .43 (stamp on barrel), presumably .43 Spanish, similar to the Mexican RB shown on P.190 of the Layman book. Wood has been replaced by sporting style, but decently. Seller claims visible rifling, whatever that means*. Receiver has decorative curved edge to top sides. So either from new as sporting rifle, or Bubba-ed. Price was OK - a bare 3-figures, worth it for the system. I just hope the barrel is usable. Photos when possible. Wish me luck!

* "visible rifling", in my experience, means anything from "as new after cleaning" down to "next stop - hacksaw". Which is why one should never pay more than a wallhanger price for online oldies!

**Whitney-Laidley?, not sure if Type I, photo too unclear.

It's arrived. And yes, it does indeed seem to be a Whitney-Laidley a.k.a. split-breech.
As for the rifling - "visible rifling" !! - make that "vestigial rifling" - it's there, intact, no gouges, but very, very thin.
Pictures when I have managed to get it to go bang!