Looking to build up some 500-800yd 300WSM loads using 168 to 180 grain bullets either Accubonds or Barnes TTSX. I have previously used Reloader 19 with some success in this gun but with 150 gr or less. What is your powder of choice for this load?

I'm using RE-22 because that's what the overwhelming majority of long range shooters recommended on www.accurateshooter.com's forum.

You should be aware that the lightest bullets I'm using weigh 190 grains. I'm driving the 190's @ 2900 fps. I'm pushing the 200 grain SMK's at 2800 fps. I have a 27.5" barrel and am reaching these velocities with powder charges that are significantly under what the books list for 26" barrels.

You really need a chronograph based on my testing. I am seating my bullets to jump .025" to the rifling. Much longer than SAAMI maximum overall length.