I don't have a chrony as yet, so I have a specific question?
For those of you that shoot the .204, and use the 39gr Blitzking and have a chrony. What velocity are you averaging with this round? Please specify charge. I'm using 2206H @ 28gr.
I chrono-ed some 39s today, out of a 26" Savage barrel. 27.5 gr. of H-4895 (same thing as your powder, I think) at 3880fps. This is plenty fast enough for my uses, and it shoots fairly well. I used R-P cases and Federal 205M primers.