Clays has big flakes but is very fast. I suspect Trail boss was modified Clays with a big Donut Hole to add volume.
I believe 800x and Blue Dot are two of the preferred powders in 223 "gopher loads". If you load for 357, 41, 44 mag or 45 colt, a pound of 800x would be well worth picking up to try in the 45-70. If it doesn't work there, it will work well with cast bullets in any big revolver case and will also work in 9mm, 38 super, 10mm etc..
I found 800x less prone to pressure spikes than blue dot in 357 mag loads.
I believe 800x and Blue Dot are two of the preferred powders in 223 "gopher loads". If you load for 357, 41, 44 mag or 45 colt, a pound of 800x would be well worth picking up to try in the 45-70. If it doesn't work there, it will work well with cast bullets in any big revolver case and will also work in 9mm, 38 super, 10mm etc..
I found 800x less prone to pressure spikes than blue dot in 357 mag loads.