Ordered an 800 grit Flex chamber hone for 308 (Midway). Completely disassembled the rifle and used the hone per instructions. It did a great job and chamber looks perfect. However it did not help with the sticky extraction. Using reformed PPU 308 brass I can not go above 39 grains. Just can't get even close to RP 150 gr CoreLok (1614 fps). Best I can do with the PPU cases is about 2400 fps. (39 gr. IMR 4064 with Hornady 150 gr. SST bullets).
I took 5 cases of the reformed PPU cases and 5 cases of RP 300 Savage cases and made some measurements:
The PPU cases hold an average of 50.5 gr. of water.
The RP 300 Savage cases hold an average of 52.2 gr. of water.
RP cases hold 1.7 gr. more water.

The average weight of the PPU cases was 175.5 gr.
The average weight of the RP cases was 158.2.
The PPU cases weigh an average of 17.3 gr. heavier than the RP cases.

Would these differences in case volume and weight explain the behavior of the PPU cases showing earlier than expected pressure signs?

Sorry. This probably should be moved to the Ammunition and Reloading section. If it is a problem maybe the moderator could move it.