Now some Rolling Block questions....

[Bigslug]

There are quite a few .50-70 Rolling Blocks for not unreasonable money on Gunbroker at present, claiming good condition, with the sights already attached. Presumably, they knew what they were doing when they set the rate of twist for the government bullet back in the day

Accurate Molds will cut blocks for you for whatever diameter you need the bullet to drop at, and you'd want to slug it to get those measurements before ordering regardless.

Seems to me like this is not a wheel you need to reinvent.

[Bulseyetom]

I had JES reboring do a Number 5 Rolling Block that I had in 250 Savage to a 50-70. The twist is 1:24 as I remember. I had to have an extractor fitted as JES does not do that. The rifle shoots Accurate Moulds 450 and 515 gr bullets lights out with 5744 powder. The 24 twist is not a problem with those boolits at all and for sure I will not be shooting 600 grain boolits until they open up a season on Wooley Mammoths! Tom