I was really glad to see Nosler publish some data on their new baby. Thanks guys for pointing that out.
I got my 100 pieces of 26 Nosler brass this afternoon from Midway USA. It has been weight sorted and primed. Now the question is what to load. Per a Kirby Allen post on here a while back, ball powders burn cooler and thus should be easier on barrels - a consideration with this chambering. Also per Kirby, ball powders don't exhibit the pressure spikes you can get with sharp shouldered cases and tubular powders.
Personally, I have found that Magnum is temp stable in my 338 RUM (I did the frozen ammo in the ice chest test). Barnes testing of Magnum and H1000 showed that both of those are temp stable and the test results are on their website. The recently released Nosler load data for their 129 AB LR shows Magnum was the most accurate powder tested.
Given all that, a fella probably ought to consider Magnum and I will however RL-33 has been nothing short of amazing in my 300 RUM and my nephew's 338 Edge so I'll also give that a look. I've had some bad experiences with AB LRs (in my 270 WSM) so I'm going with the 127 grain LRX in the 26 Nosler though I have some boxes of both bullets. The data Nosler published showing 82.0 grains as max for RL-33 has let me calibrate QuickLoad. For you guys that use the program I had to set the burn rate up about 10% to 0.305 and the WF to 0.5. The burn rate is consistent with my own lot of RL-33 but I would have figured the WF more like 0.4 so the data definitely helps.
I've seen a lot of different numbers out there for H2O case capacity for the 26 Nosler. Turns out my new primed brass holds 99.7 grains H2O. I'm guessing that will be a grain or so higher in a fired case but am using an even 100.0 grains until I get better data.
Time to turn on the scale and break out the RL-33 & Magnum!