Originally Posted by
Wise_A
I have a pretty fair amount of data available--Sierra and Hornady on my phone, Hodgdon/Alliant on the PC, Lyman #50 in the basement (and Lee #2, but I don't look at that often). Usually, I'm able to just pitch one source as an outlier and have the other three be close. I pay a little more attention to one or the other depending on the cartridge, but the main thing I look at in rifle is getting a similar bullet type.
In your case, Sierra is listing 24.9gr H335 with a 55-gr FMJBT as being hot, with no red asterisks at 24.4 (I love their app). Also, they give bolt gun-specific data.
Hornady tops out at 23.2 for all 55-grainers.
Hodgdon lists 22.7-22.8 for the Barnes TSX and Sinterfire bullets, but they go all the way up to 25.3 for the Speer Softpoint (a Spitzer).
If I were doing this for-real, I would actually get off my ass and check Lyman. But I would presume that Hornady's data is a little conservative and would probably just load 25 rounds, 5 each 22.9, 23.2 23.5, 23.8, 24.1, 24.4. Normally, I have no problem loading into Sierra's red-asterisk range, but I've never worked with the CZ mini-action, so I have no idea what it likes. Anyways, this puts your starting charges within spitting range of the uber-conservative Hodgdon data, while still getting well into Sierra's numbers.
OAL would be a couple hundreds off the lands, and I would mark each casing with the charge weight (Sharpie works great). Chronographing each load would tell me more. I would also compare the velocity to factory, and of course, examine the cases and primers after firing.