Range report load development, the good and the bad!

[michiman]

Finally got out to test out more loads for my Sako TRG 22 - 6.5 CM (26" barrel). I loaded 30 rounds with charge weights ranging from 41.5 - 42.7 gr of H4350 in 0.3 gr increments (6 rounds of each, 3 of which were with 0.001 neck tension and the other 3 with 0.003 neck tension.
Charge weight (1-5), Neck tension (A 0.001, B 0.003)
1A/B 41.5
2A/B 41.8
3A/B 42.1
4A/B 42.4
5A/B 42.7

Ill start with my frustrations! I shot my first round and my chronograph ran out of battery . Luckily i was able to borrow some for my last 2 strings (4A/B and 5A/B). I was very happy with a few of the groups (see pics). All shots were at 100 yards.

Now for the numbers
1A: No chrono data group size 0.565"
1B: No chrono data group size 0.281"
2A: No chrono data group size 0.516"
2B: No chrono data group size 0.336"
3A:No chrono data group size 0.460"
3B: No chrono data group size 0.200"
4A: average velocity 2744, SD 9.8, ES 19, Group size 0.498"
4B: Average velocity 2746, SD 9.0, ES 18, Group size 0.091"
5A: average velocity 2752, SD 7.0, ES 13, Group size 0.294"
5B: average velocity 2777, SD 12.4, ES 25, Group size 0.046"

It seems that overall my groups were tighter with the increased neck tension, specifically at 42.1 gr, 42.4 gr, and 42.7 gr. My plan is to:
1. Load 40 rounds ranging from 42.1 - 42.7 gr in 0.2 gr increments at 0.003" neck tension.
2. This will give 10 shots at each charge weight which will give me a much better sample size than the 3 I shot today. I will shoot groups with 5 shot strings.
3. Make sure I have batteries fro my chrono to get data that is useful lol.
4. Increase range from 100 yards to 200 yards

Any additional recommendations would be greatly appreciated. If anything is confusing please feel free to ask questions.

 

[Ranger188]

I knew you'd post here too.
Read response on Creedmoor forum.

 

[Sheldon N]

Nice consistent difference in neck tension, clearly 0.003 is what your gun likes. 3-4 have consistent POI, I'd split the difference in charge weight and run it around 42.3gr.

Go put some rounds out there at distance and see how it holds up. If it shoots good, you're done IMO.

Don't sweat the SD, if you're worried about perfect numbers get a better powder scale or maybe test primers. Personally, I'd just go shoot and stop testing.