@ 10:24 pm (GMT)
Bert SaenenHi Martin, thank you for your reply.
When I did try this the first time I didn't have the concentricity tool yet. My main problem with seating this long was neck tension. Three of the four test cartridges (without primer or powder) collapsed in the Redding Instant Indicator. The one test cartridge I still have has minimal runout. The needle in the concentricity tool just wiggles a bit.
FYI, these are the COAL and CBTO to jam I recorded (all with Lapua cases):
Hornady 168gr AMAX: COAL 2.896" CBTO 2.274"
Hornady 208gr AMAX: COAL 3.018" CBTO 2.281"
Hornady 178gr HPBT: COAL 2.883" CBTO 2.273"
Lapua 155gr SCENAR: COAL 2.944" CBTO 2.302"
I don't know what this says about the throat of the Tikka.
I got this procedure for load development from the AccurateShooter forums (posted by Erik Cortina in the "Long range load development at 100 yards" thread): find an accuracy node at jam minus 0.020", once you got the correct charge, test different seating depths from jam minus 0.010" to jam minus 0.040" in 0.03" increments. This sounded like a good procedure and that was what I was going to try. However, I ran into problems with the neck tension on the very long seated bullets... Will try it again, perhaps with an undersized mandrel in the Lee die. Otherwise I will have to seat the bullets deeper to start with.