I struggled for a while with the 280 grain LRX in .338 Lapua using Alliant Reloader 33 (RL-33). I collected data from 86 grains to 98 grains, and .010" off the lands to .110" off the lands. My measured case capacity (fired brass) is 7.50ml (significantly larger than QuickLOAD default). QuickLOAD consistently under-predicted muzzle velocity so be careful. I have a 24" barrel. The general results are:
- My gun shoots best at .100" off the lands and 95.4 grains of RL-33 for a muzzle velocity around 2750 fps. I'm getting about .6 MOA with a hunting rifle.
- There is a huge velocity change with seating depth (more than 150 fps), so if you are thinking of going close to the lands I would start with something less than 86 grain. The velocity is all over the place (and gets sketchy) when you get closer than .030".
- I found another reasonable load at around 92 grains of powder when .050" off the lands (as Barnes suggests generically on their website) with a muzzle velocity of around 2750 fps. The standard deviation on the velocity was still fairly high compared to the .100" loads, and it did not group quite as well, but was not terrible.
- I tried to find a good group closer to 2650 fps to be consistent with Retumbo and H-1000 data, but the RL-33 just would not group well below 2730 fps in my rifle.
Hope this helps someone out, I searched very hard and could not find info on this load. Barnes has not tried it, neither has Alliant. I was shocked to find such a huge bullet jump to be the optimum, and it was one of the last things I tried.