Doing a couple of ladders for a 6.5G AR and had to move to a new bullet lot from ladder 1 to ladder 2. Bullets are 123gr. Hornady ELD-M, using Redding dies.
Found something I find very peculiar:
Everything is identical other than powder type and weight: processed at the same time, through the same dies without adjustment, and press etc. Was targeting a COAL of 2.260 as a first go.
Lot A (loaded 50 rounds):
Adjusted die to: 2.260 OAL = 1.688 CBTO
These 50 rounds measure quite consistently
Lot B (loaded a handful before I noticed this):
Did not change seating depth on die: 2.270 OAL = 1.678 CBTO
From Lot A to Lot B the same process resulted in a COAL increase of 0.010" BUT the CBTO has decreased 0.010". I'd be surprised enough by the OAL moving .010" but to see the CBTO move .010" in the opposite direction has me confused. I was expecting to see the CBTO increase the same .010"....
Does this make sense or am I making a big deal out of nothing?
Found something I find very peculiar:
Everything is identical other than powder type and weight: processed at the same time, through the same dies without adjustment, and press etc. Was targeting a COAL of 2.260 as a first go.
Lot A (loaded 50 rounds):
Adjusted die to: 2.260 OAL = 1.688 CBTO
These 50 rounds measure quite consistently
Lot B (loaded a handful before I noticed this):
Did not change seating depth on die: 2.270 OAL = 1.678 CBTO
From Lot A to Lot B the same process resulted in a COAL increase of 0.010" BUT the CBTO has decreased 0.010". I'd be surprised enough by the OAL moving .010" but to see the CBTO move .010" in the opposite direction has me confused. I was expecting to see the CBTO increase the same .010"....
Does this make sense or am I making a big deal out of nothing?