Well, I had to call Hornady today to ask a question about setting up one of their dies so I asked if they had any data for this combination. The tech was very helpful and found the following in an older Hornady manual:

4.8gr min up to 6.4gr max @ 1,100 fps

Please DO NOT take that as gospel! 6.4 grains looks hot to me based on everything else I've seen.

I just loaded 25 @ 4.8 grains and 25 @ 5.0 grains so we'll see what the chronograph says. Hopefully, it'll stop raining sometime this weekend.