Specifically with 100 grain bullets?

My daughter will be hunting mule deer for the first time this year (12 years old) and I am putting a load together for our .243 Winchester using 100 grain Hornady BTSP bullets. I have serveral suitable powders on hand, but I was given a lb of RL19 in a horse trade and I don't have any other use for it at the present time. Thought I might give it a try instead of using up stashes of my powders preferred in other cartridges (IMR 4831, IMR 4350, H1000, RL22 and IMR 7828).

Thanks.