Back when I worked up my 270 grain load, I was after the same MV as my 180 grain load in my .30-06.

That ended up being 75 grains RL-15 and a large rifle primer for ~2750 fps. Using a 215 primer was fine, but the 210 grouped measurably better.

I just got some more RL-15, so keep your eyes peeled and crawler bot working overtime...

It's you and the bullet, and all the rest is secondary.