has anyone found some 45-70 loads using clays or unique type powders
with lighter bullets (350).

brianmp I would stay away from powders that needs fillers. To me just makes NO sense when you have other powders that fill the cases for milder loads and no fillers no chance of ringing a barrel.use powders Like 3031 or rx7 or 5744.
The CUP pressures are up and no gain in velocity with those faster burners THE other thing is accuracy you have a shooter most (likely) so thats my 2 cents NEXT!

just a note about wads I was shooting 31.0 of 4198 and a 350 gr cast bullet and grouping 2"
at 100 yds. I added a lubed felt wad and it doubled my group sizes. I asked about clays etc.
because i have a lot of it.
thanks

For 45/70 or 45/90 use a dry .046 dia veg wad. Wayne

You want a nice mild load,lots of fun to shoot and accurate..

Here you are..I shoot 14 grains of Unique with a 416 grain
cast bullet and it is fun..I do put just a small piece of tissue
paper in the case to hold the powder on the primer..A pencil
will work for that..I have shot woodchucks with this load out
to 100 yards..Great for trigger practice of hand