I'm probably going to regret this, but the way I'd go at it is to moly up some 162s, seat them to just kiss the lands at whatever length that turns out to be in my rifle, get out my five pounder of '15 and chrono and starting a bit low keep adding fuel (while watching for bad signs) until 2700 is reached by my rifle.

Your rifle, his rifle and my rifle may require different tweaks of the parts of the recipe to cook up the same dish.

I'm going for my flame proof suit now.