New to load development. Some advice on this data, please.

[Jefe's Dope]

6.5 CM
Once fired Lapua Brass
CCI 450 primers
H4350
Berger 140 gr. Hybrid Match
Tikka Tac A1 24" factory barrel
Magnetospeed V3 chrono
2.877 COAL/2.188 CBTO
*5 shot groups

41.7 grains
2700 avg.
SD- 7.4
ES- 19
.53 MOA

41.8 grains
2712 avg.
SD- 7.4
ES- 21
.85MOA

41.9 grains
2722 avg.
SD- 7.1
ES- 17
.52 MOA

42.0 grains
2727 avg.
SD- 7.4
ES- 18
.65 MOA

42.1 grains
2733 avg.
SD- 5.9
ES- 15
.53 MOA

42.2 grains
2737 avg.
SD- 5.9
ES- 15
.59 MOA

42.3 grains
No Data
.52 MOA

42.4 grains
2758 avg.
SD- 5.8
ES- 16
.72 MOA

42.5 grains
2764 avg.
SD- 8.2
ES- 20
.39 MOA

42.6 grains
2779 avg.
SD- 15.2
ES 40
.37 MOA

No signs of overpressure.

 

[Jefe's Dope]

Some other data but different brass and bullet. Posting for FPS comparison.

All above specs apply accept:
Twice fired Hornady brass
CCI BR2 primers
Hornady 140 gr. ELD Match bullets
2.795 COAL/2.186 CBTO
*3 shot groups

41.7 grains
2734 avg.
SD- 13.3
ES- 23
.33 MOA

41.9 grains
2750 avg.
SD- 12.0
ES- 24
.53 MOA

42.1 grains
2748 avg.
SD- 4.5
ES- 11
.67 MOA

42.3 grains
2770 avg.
SD- 7.4
ES- 15
.60 MOA

42.5 grains
2778 avg.
SD- 22.0
ES- 44
.47 MOA

42.7 grains
2786 avg.
SD- 9.0
ES- 18
.58 MOA

 

[Supersubes]

Not sure what you’re needing help with, but it sure seems like you mislabeled the Hornady brass loads (backwards). So 41.7 was actually 42.7, and you descended from there.

 

[Diver160651]

Trying to do load development this way, is not the best.

Two few rounds and is a throw back to the early days of intergrading chronos in load development paying more attention to it than anything else. Yes, you can get something that works, but OCW in combination with ladders works better. More rounds but better. It helps over come NT issues, especially for those with no way to accurately judge NT (neck tension).

 

[Jefe's Dope]

Not sure what you’re needing help with, but it sure seems like you mislabeled the Hornady brass loads (backwards). So 41.7 was actually 42.7, and you descended from there.

Good catch. Thanks.

 

[Hawk in WY]

Nice shooting.

You're working a very narrow window with increments so small they might overlap with even a very small variation in powder charge.

My suggestion would be to expand your range to maybe three or four grains and test steps of .2 or .3 grains looking for a low and high node based more on where three loads impact on the target near the same place rather than group size. You can tighten group size later with seating depth.

If you really want to use your chronograph, load ten rounds .2 grains apart and look for flat spots in velocity.

I also agree OCW and Ladder methods of load development will give you better data.

Good luck.