Lyman cast/smokeless data for 45-90

I have the Lyman 50th manual and have been planning to load some smokeless cast rounds for my 1886 win/miroku in 45-90. This is just to get started and I'll start playing around with BP soon.

Anyway, I am wondering if the cast and smokeless load data that is in the Lyman for this cartridge would require fillers in the case? Sure not... I think I read earlier in the book a statement about never doing that.

Anyway, I have a 405gr cast bullet that is very similar to the Lyman 457193 pattern. It might actually be the same. It's MBC's buffalo#1 bullet. I was planning to use some 4198 that I have. Even they don't have this bullet listed for the 45-90, they have a similar 400gr bullet and the data for that is very very similar to the 405gr bullet I speak of when looking at the 45-70 data. So, I figured it should also be very similar in this case. I measured out their starting charge today to see what case fill would look like and it's a pretty poor case fill with a large amount of space. I would expect poor velocity spreads with so much space, but it is of course a safe load without using a filler for the exact bullet, powder, etc listed, correct?

If you have some 5744 or Shooters World Buffalo powder, it's supposed to be position insensitive (according to Western Powders manual), not needing fillers to hold the powder against the primer.

I'm with Norske, and here's some 5744 data for you, as well.

https://i.imgur.com/bdf9x3k.jpg

As indicated above be VERY careful about what powders you use in your 1886 45-90 lever action rifle. Either the Accurate 5744 or the Buffalo Rifle powders can be used without fillers or kapok. I have used both. Almost all other powders will require the use of Kapok or a similar filler.
I'm here to tell ya that a full case of compressed black powder is no light weight charge. With the 330gr Gould Express Bullet, you will know you lit one off. Be sure to measure the COAL to ensure it will cycle through the action. a 400gr bullet is about the max you can get in the case and have it cycle through the action.

https://youtu.be/8DPkrY5w6rQ