Bullet Seating Depth

[LRRPF52]

Before you shoot those, did you check where or if you are jamming into the lands with the 120gr NBT? Color the bullet shank to ogive area on a dummy cartridge loaded to that COL, and see what happens when you chamber it. If there are land markings on the bullet, and it is difficult to extract, you are jammed into the lands, which will cause significant peak pressure with anything even near a max load, and you probably don't want that.

Did you load the 120gr NBT's to 2.285", or the 123gr Hornady's?

I just looked over 28 different 120gr NBT loads from forum members and industry sources, and all of them but one are 2.225"-2.250". Most are 2.240" COL.