175 SMK's or the 178 BTHP's if you can find them anywhere. The SMk will keep up till about 500 yards then the 178's bc takes over. Damn Hornady for stopping the production of them.
One of my favorite loads is the horandy 178 bthp over 43.2 grains of 4064 in lapua brass withe a 210 primer. Shoots bug holes and runs 2700 according to the magneto speed.
I just got the magnetospeed v3 and its the shit. I should kick myself in the ass for waiting so long to pick one up and wasting time with my old chrony.
You trim your cases back so they will fit in your chamber. Anywhere between 2.005 and 2.015 is supposed to be safe to fit. Jamming the bullet right against the lands adds increased pressure of the round, so I would start a bit set off and work up.