H1K worked great for me as well.
The normal 180 grain load data is where I started, started from that point.
The 180's work great too. Just whatever your rifle likes best.
Just found this thread. I have the VX-5HD 3-15x44 CDS FireDot Duplex. I have it mounted on a CA Ridgeline in 6.5-PRC. This combo works well together. Hopefully, everything goes well for you.
Take care
I'm passed twenty by forty-five more.
No flat brimmer here.
By age twenty, I had a half dozen deer under my belt. Going to college and working full time.
Life is good!