Blackpowder may resolve your issue even with your "standard alloy". In the spring one year, I found 457125s with the nose fully engraved, and they were too hard to scratch with a thumbnail. It seems a couple of hardcore BPCR shooters were testing, and shot hard bullets including linotype, while there was a fair amount of snow on the banks. Back in those days, mid '90s, they were shooting Elephant and Goex in their 45-70s.
Regarding paperpatch, I borrowed a Tom Ballard 45cal 500gr (?)tapered PP mould from a guy and cast some. I don't recall, but probably 25-1, patched with high cotton content rag paper, loaded over Goex ffg or Ctg, and shot through my scoped Ruger #1 45-70. I don't think there was 1/4" of bullet in the case, and they thumbed right into the bore. Recoil was....ferocious....but shot quarter sized groups at 100 yards.
There is a bit of learning curve for shooting real BP, but it can be pretty simple. Large pistol primers (!), minimal sizing of cases, loading BP by volume through a droptube, over powder card wad, compressing powder, and seating the bullet. I preferred just enough neck tension so as to have "cartridges", but some guys liked lots of neck tension while others loaded "slip fit". It IS necessary to decap and wash your cases between loadings. Wiping between shots isn't necessary if you have a lube that works with BP fouling and your humidity, but a blowtube is almost a necessity.