I have made shot loads out of 44 Mag brass that worked well in that caliber and cost nothing to load. Something similiar would work for your 45-70, if nothing else to see how the pattern turned out.
As far as more power, from the little bit of testing I have seen, there is not a big difference in penetration for the added velocity, even w/ hardcast or solid bullets. In my small mind, you will not gain anything special by adding a few hundred fps. Once you get over 1300 fps or so, penetration increases very slowly w/ velocity. Once you get over 2500 or so, it increases even more slowly.
BTW, peeps sure keep the gun handling nice.
As far as more power, from the little bit of testing I have seen, there is not a big difference in penetration for the added velocity, even w/ hardcast or solid bullets. In my small mind, you will not gain anything special by adding a few hundred fps. Once you get over 1300 fps or so, penetration increases very slowly w/ velocity. Once you get over 2500 or so, it increases even more slowly.
BTW, peeps sure keep the gun handling nice.