If you haven't loaded bottle neck rifle before be aware you will need to trim the cases.
I have a Worlds Finest Trimmer (WFT) not cheap but it makes trimming .223 brass much less of a chore and with a semi auto you will probably have a bunch of brass to trim.
H335 should work well with the 55s
You have a different bullet of course but here is some data from Hodgdon
55 GR. SPR SP Hodgdon H335 .224" 2.200" 23 3018 40,800 CUP 25.3 3203 49,300 CUP
Start 23gr, MAX 25.3
Lyman 50 shows
Start 24.3 MAX 27.0 with a different 55.
Lymans data seems a bit hotter than Hodgdon or Sierra, I think I would use Sierra or Hodgons data.
View attachment 933633
Need to try to find my notes but I was thinking I ended up loading 24.7gr H335 with a 55 for my Mini.
Always start at the start charge and work up to be safe.
If you Mini is like mine it will throw the brass a little
(mine is like 15' or more), Nice positive ejection on my Mini