I wanted to add some info to this thread. I've been working on a load for my 6.5 Creedmoor over the last few days using RL26, 147 eldm, and Lapua brass. Here is what I found.
Rifle:
Bighorn TL3
23" Bartlein Heavy Palma 1-8" barrel
Manners T4A
Built by Phoenix Custom Rifles
I ran the first OCW from 44.0 to 47.2 grains of RL26 using once fired Lapua brass and CCI 450 primers. As a side note, I tried working up a load last year for another rifle using Lapua brass and CCI 450 primers and was not happy with the lack of consistency in velocity. That load was with RL16 and Berger 140 hybrids. I finally switched to Norma brass with F210M primers and the same load was a tack driver with very solid velocity and low ES/SD.
OCW - 1 (3 shots at each load)
147 ELDM, RL26, CCI450, 1x fired Lapua brass, .020" jump
Load / Avg Vel / ES / SD
44.0 2653 37 18.9
44.4 2693 16 8.0
44.8 2727 21 11.6
45.2 2739 31 16.3
45.6 2770 36 18.1
46.0 2799 35 18.5
46.4 2816 54 27.2
46.8 2845 3 1.7
47.2 2874 31 16.5
The above were all 3 shots per charge weight. As you can see, velocity was good but ES and SD were all over the place. As far as the ocw, it appeared that there was a node from 46.0 - 46.8 based on center point of the groups of those charge weights.
I decided to run another OCW running from 46.0 to 46.8 in .2 increments. I also wanted to try a different primer, just to see if the CCI 450's could be causing the erratic velocity numbers, so I bought some CCI BR4 primers to use on the second round.
OCW - 2 (5 shots at each load)
147 ELDM, 1x fired Lapua brass, CCI BR4, RL26, .020" jump
Load / Avg Vel / ES / SD
46.0 2827 25 9.9
46.2 2832 21 9.5
46.4 2848 21 8.2
46.6 2857 33 11.8
46.8 2882 30 11.7
These were all 5 shots per charger weight. A couple of things I noticed. First, the velocity is more consistent with the BR4's. Second, the velocity is about 30ish fps higher with the BR4's at the same charge weight.
Group location in relation to the poi was the same for loads 46.0 to 46.6. Load 46.8 was located down and a bit right on the target. I think the node falls off on my gun at that point. None of the groups were particularly tight. I ran both ocw's at .020" jump, so I'm sure the groups would shrink with some tweaking of seating depth. Group size ranged from 1/2" to about 1".
Last year I worked up a load for a Christensen Ridgeline 6.5 CM. It was 41.8 grains of RL16, 140 Berger Elite Hunters, Norma Brass, and F210M primers. This load shot really well out of the Ridgeline. After finishing the ocw, I decided to shoot 5 rounds of this load out of my Bighorn just to see how it would shoot. 5 shots were in one ragged hole (about 3/8"). Velocity was 2814 average, ES of 15, and SD of 6.9 for 5 shots. I don't know how far the bullets were jumping. Although the 147s with RL26 seems promising with the velocity. I think my next step will be to stretch it out on steel and do a comparison between the 147 eldm with RL26 vs the 140 Bergers with RL16.
