I've reloaded for several years with good success in .308 but I am struggling with the 6.5 creedmoor.

I have the following results taken by a magneto speed chronograph which includes SD and extreme spread. I was under the impression that the lower the SD and ES; the better.

But although today's groups were far from excellent, there were several loads with good SD and ES that did not group very well at all.


I'm sensible enough to understand that I can see that the groups aren't great but I expected better with some pretty good chronological readings. any thoughts? Is it a case of barrel harmonics and the load not being suitable?



Series 1 Shots: 5
Min 2750 Max 2772
Avg 2765 S-D 8.8
ES 22

Series Shot Speed
1 1 2767 ft/s
1 2 2750 ft/s Group Size: 0.47 MOA
1 3 2770 ft/s
1 4 2772 ft/s
1 5 2769 ft/s
---- ---- ---- ----


Series 2 Shots: 5
Min 2757 Max 2775
Avg 2768 S-D 7.4
ES 18

Series Shot Speed
2 1 2775 ft/s
2 2 2773 ft/s
2 3 2766 ft/s Group size 0.44 MOA
2 4 2757 ft/s
2 5 2773 ft/s
---- ---- ---- ----


Series 3 Shots: 4
Min 2727 Max 2761
Avg 2742 S-D 15.4
ES 34

Series Shot Speed
3 1 2761 ft/s
3 2 2727 ft/s
3 3 2749 ft/s group size : 0.7 MOA
3 4 2733 ft/s
---- ---- ---- ----


Series 4 Shots: 5
Min 2731 Max 2745
Avg 2737 S-D 6.1
ES 14

Series Shot Speed
4 1 2745 ft/s
4 2 2735 ft/s
4 3 2731 ft/s Group size: 1.1 MOA
4 4 2732 ft/s
4 5 2742 ft/s
---- ---- ---- ----


Series 5 Shots: 4
Min 2720 Max 2740
Avg 2731 S-D 8.6
ES 20

Series Shot Speed
5 1 2729 ft/s
5 2 2720 ft/s
5 3 2735 ft/s group size 1 MOA
5 4 2740 ft/s
---- ---- ---- ----


Series 6 Shots: 5
Min 2729 Max 2752
Avg 2736 S-D 9.1
ES 23

Series Shot Speed
6 1 2752 ft/s
6 2 2733 ft/s
6 3 2729 ft/s Group size : 1.2 MOA
6 4 2731 ft/s
6 5 2736 ft/s
---- ---- ---- ----


Series 7 Shots: 4
Min 2705 Max 2728
Avg 2717 S-D 9.4
ES 23

Series Shot Speed
7 1 2719 ft/s
7 2 2705 ft/s Group size: 1.23 MOA
7 3 2716 ft/s
7 4 2728 ft/s
---- ---- ---- ----


Series 8 Shots: 5
Min 2700 Max 2724
Avg 2713 S-D 10
ES 24

Series Shot Speed
8 1 2724 ft/s
8 2 2700 ft/s
8 3 2721 ft/s Group size 0.55 MOA
8 4 2706 ft/s
8 5 2715 ft/s
---- ---- ---- ----


Series 9 Shots: 5
Min 2712 Max 2734
Avg 2722 S-D 9.6
ES 22

Series Shot Speed
9 1 2731 ft/s
9 2 2712 ft/s
9 3 2718 ft/s group size: 1.13 MOA
9 4 2716 ft/s
9 5 2734 ft/s
---- ---- ---- ----


Series 10 Shots: 5
Min 2705 Max 2732
Avg 2717 S-D 11
ES 27

Series Shot Speed
10 1 2732 ft/s
10 2 2705 ft/s
10 3 2707 ft/s Group size: 0.88 MOA
10 4 2720 ft/s
10 5 2721 ft/s