A re-barrel project on a Lo Wall from .45-70 to .257 Roberts or .260 Rem.

There is a change in case head diameter. Does this present any problems?

Will have to get a different extractor from browning. Going from rimmed to rimless will require change.

The .45-70 should be on a high wall action instead of low wall, as should the .257 and .260.

dave

High wall opposed to low walls, due to pressures?

Due to bolt thrust, because the low wall breech block is not fully supported by the action walls behind the cartridge. Bolt thrust is the product of pressure times cartridge base area, so both pressure and case head size count.

Browning, I believe, did not make .45-70 on low wall. I don't know what the ultimate strength of the low wall action is, but generally larger and higher pressure cartridges they built on high wall, smaller and lower pressure ones on low walls.

dave

I misspoke and called it a low wall. Thanks for the good info.
I have learned the .260 was offered as a low wall, as was the .243 but your point was a good one.