Yep; Vihtavuori and blackpowder is pretty much what we have to play around with, this side of the pond.
I downloaded this .45-60 data from the homepage of Chaparral, several years ago:
300 gr. Sierra .458" FN Hollow Point: 46 grains VV N135.
330 gr. Chaparral Arms bullet .459": 45 grains VV N135.
400 gr. (no make given) .458": 41 grains VV N135.
330 gr. Chaparral Arms bullet .459": 47 grains VV N140.
All the above loads are listed as loaded in Chaparral cases, and primed with CCI primers.
(I have assumed that the 330 gr. "Chaparral Arms bullet" is an all lead bullet...)
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I own an Uberti 1876 in .45-60 caliber, and I have loaded cut-down Winchester .45-70 brass with Federal primers. Bullet was the LEE 330 grain FN cast from wheelweights. I used 43 grains of VV N135.
I like the N135; it fills the cartridge case almost completely and has given me no unpleasant surprises.
I use it for .38-55, .45-60 and .45-70.
The N133 could also be used, it is a little hotter than the N135, so loads should be reduced accordingly.
The N140 has always been a typical powder for the .308 Nato etc. in my eyes.... I've never tried it in any of the old blackpowder cases.
https://www.vihtavuori.com/powders/n100-powders/