I'll probably get flammed for it, and I want to preface by saying that they *ARE NOT* direct substitutes for each other. However, a lot of guys that run H4350 and Reloader 16 in the Creedmoor-class cases are running charge weights that are pretty close to each other.
I had to do the same as you with RL-16 in my 6.5x47L. I got similar velocities with 38.8gr RL-16 as I did with 39.4 of H4350. Hodgdon listed H4350 at 40.5 max, so I dropped 5% (~38.5gr) and started there, looking for pressure signs. I went up to 39.5, but accuracy was best at 38.7 - 38.9. Zero pressure.
I'd look at the H4350 data, reduce max by 5% again, and start your load development from there. So maybe at about 39.5.
Bolt Action Reloading on YouTube shot up to 41.3gr of Reloader 16 under a 110gr A-Tip.
Hopefully somebody here has more experience than me and can chime in with actual numbers.