How many bullets do you have down the barrel? Also, I think the RPR is 26" on the barrel, correct?
Last weekend I helped a friend do load development on his carbon-barreled hunting rifle (26" Bartlein barrel - the whole rifle weighs like 6 lbs!). Factory 225s were getting him in the low-mid 2900s (~2930, if I remember correctly). So, 2850 on the factory 225s seems a bit on the low side. And we found a good node at ~2880-2900 with the ladder.
Interestingly, the factory ammo out of his rifle shot horribly - and I mean HORRIBLY. He was lucky to get 1.5 MOA on a 5-shot group - and it's not him, or me, because he's also had other competition shooters get the same results. He wasn't planning on getting into reloading now, but I convinced him to let me load up a ladder using RL26 and Berger 230s. The ladder was very consistent (and actually better groups throughout the whole ladder than Hornady factory!).
As mentioned, we found a node at the 2880 range, then tried to load some rounds at the range to validate. Unfortunately, the wind was really blowing and it was tough to get the portable scale just right, so the validation rounds were a bit hot at just above 2900, but they still grouped okay (and had a 5 SD...). I'm loading up some more for him at the proper charge weight for the next trip.
And oh yeah, he's ordering reloading stuff