The weird thing about LVR: it seems to improve SD/ES the closer I get to max. I don't know why, but if I do mild charges between 26-28gr I get pretty big numbers, but when I start to approach 30gr they improve significantly. I may just be an outlier though.
This is very true, definitely not just an outlier. I've been saying this here for years now - Lever burns cleanest and gives the smallest SD when run right up to max. If you're going to use Lever, load it near max. If you want mild loads, there are other powders that work better for that.
In most situations near max is where Lever gives the best accuracy as well. That's what makes it such a great powder for high velocity loads - it's super easy to load with if you follow basic load development practices and a couple peculiarities*, and you won't find another powder capable of more velocity safely, within the appropriate applications of course. CFE223 was mentioned earlier - it comes close to Lever's velocity, but is not as forgiving at max pressure and often doesn't exhibit the same trend in SD and accuracy.
The main peculiarity of Lever is that it makes a LOT of gas, so adjustment of an AR's gas system is mandatory. The people who claim it's really dirty or gives high SD are often the people who didn't adjust their gas system, and had to stop at a lower pressure charge because they're seeing false pressure signs due to early unlocking. Restrict the gas a little more and you'll see those false pressure signs go away. A heavy buffer is not enough.
The other peculiarity is that in my own testing, it's proven to be temp sensitive in a linear fashion down to about freezing temps, and then flattens out below that. I typically develop a summer load and a winter load with Lever for the year-round cartridges; others are only used seasonally so no need. If you want a temp stable powder for 6 ARC, then 8208 is the best bet but good luck finding it right now, and you'll give up velocity in the small 6 ARC case compared to Lever.
Also for the OP - if you're getting rid of the Grendel to reduce the number of powders, don't. The Grendel and 6 ARC share a lot of the same powders, including Lever as the top velocity performer for both with mid-heavy bullet weights.
I use Lever in a wide range of cartridges; most of these don't have published data for them but if you're comfortable with load development, the results don't lie. Here's what I use Lever for:
20 Tactical
223 / 5.56 (69gr+)
6mm-223
6mm ARC / 6mm Grendel wildcats
6.5 Grendel
6.8 SPC
30/30
308 / 7.62x51
35 Remington
35 Whelen
