If so are at or below the minimum for the 400 grain Barnes Originals?

I bought 100 to play with.

Buster bullet is really long for weight. They eat up a lot of the volume in a 45/70 case. Depends on the powder you are using and charge.

Even with a compressed load of ball powder I had to cut back a bit on powder compared to the Woodliegh 400s. (sorry, I don't load the original Barnes)

IMHO the best bullet going anywhere in a lever action 45-70 is the North Fork 350gr flat nose.
You can get plenty of powder in the case and it
is a real thumper with plenty of penetration.

Good Shooting

Tetonka
DRSS
Band of 45-70ers
Bolt Trash Club

he is correct drop down to a 300 or 350 gr quality bullet..plenty for anything with a good charge of powder behind it...bullet construction is more important than weight.
I do load a 400 gr bullet over 53.0 gr of IMR3031 with a Fed 215 primer for moose in a Marlin 1895

Hopefully will a report on moose and black bear.
Heading northwest, next weekend. Taking my 45/70 XLR.
I'll have load notes as well.
I've built a portable reloading press.
My buddies have 45/70 guide guns.
So in the afternoon we'll break out the chronograph and test loads.

Also when the buster and ftx are side by side, the ftx is longer.