I have a couple of Weatherby's one in 257 Weatherby Mag MARK V DELUXE and one 300 Weatherby Mag. in the LASERMARK MARK V DELUXE you can ck this link: (Mark V® Lazermark | Rifles | Products | Weatherby.com
I have done very extensive load test on these rifles and have all the resulting data for them. That being test targets, chronograph velocity's, and load recipes that performed best.
I have the regular die set, the neck seizer die, the special factory crimp die, and around a 100 rounds of fire formed custom annealed brass for each. I have a few of the test bullets that performed best in the test's. if your interested.