6.5x.284 might be a bit much for PD's. Barrel life of that round seems to be a thousand or less, and I have heard of guys shooting that in 3 days of Pdogging. The 6br might be a good compromise, or one of the variants- I am not familiar with the brx's dashers, and so forth. Hard to beat a 22-250 for PD's. .243 is something else you could look at for dual purpose- it will get to 1k fairly convincingly from what I read.
Bookmarks