Normally I cook mine at 400 (Oven setting. No thermometer. I'm sure it lies a little bit.) for 30 minutes (starting in a cold convection oven) and they come out great. HF red. (I'm not advocating for this powder. It's hard to work with but it's what I have on hand and I feel like I have to use it up. Figured I should disclose that detail, though.) Needed slightly harder boolits and didn't want to mess with my perfect record of being cheap by spending any money adding tin and/or antimony. (Using range scrap.) So I experimented a bit with heat treating. Found out I can get away with 450 for an hour, with no harm to the pc, before chucking the basket in a bucket of water. Also found I can wait at least five hours before sizing without losing any harness. (Sizing before, immediately after, or five hours after made no difference in hardness at 24 hours after dropping into the water.) Didn't experiment with any longer than five hours before sizing. Didn't really mean to do that experiment either but life happens. My three month journey into casting for the 9mm ended with groups of 10 making one ragged hole at 50'. (multiple targets....repeatable)
Seems to be quite a bit of flexability when it comes to cooking the pc.