Tim,
I've done no work with the 6.5/284 but quite a bit with the 6.5x55.
In the 6.5x55 with a 26" barrel the N165 gave by far the best velocities (2940 with 142s at 49.5 gr) but consistency wasn't great and it seemed to be a bit temp sensitive.
4350 seems a bit fast and was a non performer.
The most consistent powder in the 6.5x55 seems to be 4831sc. 47-48 grains gives right around 2800 and consistency is good.
A fellow competitor used 4831sc in his 6.5/284 but felt that it generated too much heat (maybe). He switched to 3100 ans was getting in the mid 2900s with (as I recall) about 55 grains of it.
All of these midsized 6.5s seem to show a marked prefernce for one primer or another so don't be afraid to experiment with different types as a means of tuning out vertical.GD
