I am once again stuck. I mixed up SD and ES and thought I was on the right track but now I'm not so sure. I finally bought a Magnetospeed instead of a cheap pro chrono.
.223 Lapua brass, 75 grn Hornady HPBT, Varget, shot out of a Tikka t3x.
Brass is on it's second firing. I bumped the shoulder back .002/.003 and trimmed brass OAL to within .001 of each other, and seated the bullet to max mag length.
I am attempting to use Cortinas method, and thought I had a good powder charge with a decent SD, but then realized the ES is still really high and I don't know why.
22.5 grn (SD 15.4, ES 32)
2658
2681
2664
2654
2690
23 grn (SD 25.5, ES 67)
2709
2722
2776
2732
2765
23.3 grn (SD 28.4, ES 64)
2769
2833
2807
2774
2770
23.5 grn (SD13.8, ES 36)
2788
2801
2792
2765
2778
23.6 grn ( SD 11.3, ES 22)
2831
2828
2847
2849
2853
23.7 grn (SD 23.6, ES 55)
2805
2860
2818
2800
2820
23.9 (SD 14.6, ES 34)
2827
2828
2848
2861
2849
23.6 grn looked the best so I went back and did 0.1 grn up and down, and it was worse.
Any ideas why my ES is so high? Should I start playing with seating depth at 23.6, or would that be considered unstable since it's 0.1 grn close in either direction to horrible? 22.5 produced a group where they were all touching (except one) but I should avoid falling for that "trap" with a high ES right?
Thanks
.223 Lapua brass, 75 grn Hornady HPBT, Varget, shot out of a Tikka t3x.
Brass is on it's second firing. I bumped the shoulder back .002/.003 and trimmed brass OAL to within .001 of each other, and seated the bullet to max mag length.
I am attempting to use Cortinas method, and thought I had a good powder charge with a decent SD, but then realized the ES is still really high and I don't know why.
22.5 grn (SD 15.4, ES 32)
2658
2681
2664
2654
2690
23 grn (SD 25.5, ES 67)
2709
2722
2776
2732
2765
23.3 grn (SD 28.4, ES 64)
2769
2833
2807
2774
2770
23.5 grn (SD13.8, ES 36)
2788
2801
2792
2765
2778
23.6 grn ( SD 11.3, ES 22)
2831
2828
2847
2849
2853
23.7 grn (SD 23.6, ES 55)
2805
2860
2818
2800
2820
23.9 (SD 14.6, ES 34)
2827
2828
2848
2861
2849
23.6 grn looked the best so I went back and did 0.1 grn up and down, and it was worse.
Any ideas why my ES is so high? Should I start playing with seating depth at 23.6, or would that be considered unstable since it's 0.1 grn close in either direction to horrible? 22.5 produced a group where they were all touching (except one) but I should avoid falling for that "trap" with a high ES right?
Thanks