Worked up a load with R17 under a 185gn Berger OTM came in at 49.5gn. The fps was unreal at first that came in at 2763 10 shot average. The brass is match Hornady and the bullet is just touching the lands. My rifle is a bone stock 5R 24" barrel, and so far I love the load. It's held 2" groups at 500 yards. Need to put more time behind the load but the rain has not allowed it.
I'd start at around 47gn depending on the over all length you are wanting to use. If going with a short mag fed bullet drop around 2 more grains.
Hint even tried the 2000mr and didn't like it, had a heck of a lot more kick to it than R17. Too much pressure at the pop of the primer for me, I like how R17 shoots like a slower burning powder, less kick. ( more like a slow hard push than a straight up mule kick.