Here's my reloading 6.5 Creedmoor report for my 18" piston gun.
So, took my ladder of 10 steps of 5 rounds each, COL of 2.820, BR2 primers, Hornady 1x fired brass, 140 ELD-M's, spaced at .3 grains of StaBall 6.5 loaded from Max of 44.0 down to 41.3 grains to the range today, along with 4 steps of 5 rounds, same as above but with COL of 2.800, grains from Max of 43.7 to 42.8. I also shot 5 2020 factory Hornady Match 140's that give me both pressure and early extraction signs, and Hornady confirmed they were loaded with RL16.
No pressure or early extraction signs on my reloads. Maybe thanks to Clint at
heavybuffers.com for the 8.5 oz weight and stiff spring.
This is from an 18" barrel on an Adams Arms P2 that's Omega 300 suppressed and slightly customized.
Also had some issues with the used Magnetospeed Pro that Scheels sold me as new. That's going back to them tomorrow. So, not all shots were recorded.
So....4,640' altitude, average 56 degrees.
Factory Hornady, 2662 avg, ES=9, SD=4.0, COL was 2.814
COL 2.820, 41.3 grs, 2543 avg, ES=68, SD ??
COL 2.820, 41.6 grs, 2536 avg, ES=23, SD=9.4
COL 2.820, 41.9 grs, 2550 avg, ES=16, SD=7.5
COL 2.820, 42.2 grs, 2567 avg, ES=11, SD=5.0
COL 2.820, 42.5 grs, 2574 avg, ES=38, SD=15.2
COL 2.820, 42.8 grs, 2615 avg, ES=37, SD=16.8
COL 2.820, 43.1 grs, 2605 avg, ES=38, SD=18.8
COL 2.820, 43.4 grs, 2634 avg, ES=52, SD=21.4
*** COL 2.820, 43.7 grs, 2683 avg, ES=52, SD=21.4
COL 2.820, 44.0 grs, 2675 avg, ES=48, SD=20.7
†************
COL 2.800, 42.8 grs, 2626 avg, ES=42, SD=29.6
COL 2.800, 43.1 grs, 2643 avg, ES=53 (2 shots, 2669 & 2617)
COL 2.800, 43.4 grs, 2651 avg, ES=55, SD=20.0
*** COL 2.800, 43.7 grs, 2673 avg, ES=6, SD=2.8
All shot okay groups at 100, but frankly I was so pissed at the Magnetospeed that I wasn't really trying so only shot sub MOA on the two 43.7 grain loads. Those were the ones I liked best so I'll load that and test COL differences another day. I don't trust some of the SD numbers it spit out either.
Peace.