Reloading a 275 Rigby here with North Fork Flat Point Solids 160 gr. My measured CBTO is 2.460 with my seating die all the way out it buries the ogive into the case mouth. So with no way to measure this I went COAL and the furthest out I can seat the bullet is .293 off the lands. This seems extreme and even starting at 4% under minimum per manufacturer recommendations I don’t think I could get much more powder in the shell. I’m fairly new to reloading, any recommendations?