BTW, I went back and looked over my data to be sure; my preferred Lever load with that 123gr ELD was running at 2,385 fps in my 12.5", so you're in the ballpark. Personally I don't go by primer appearance unless it's extreme, because there's too much variation between different kinds of primers, flash hole sizes, etc; the brass tells me what I need to know - particularly life of the primer pocket, as well as any ejector hole imprints (not swipes, but permanent imprints). If my brass is loosening primer pockets within 4 loadings, I figure that's a max safe load for anything in an AR, and a bit over for a Grendel. I prefer to get 8-10 loads from a piece of brass, which that 2,385 fps load did for me when I was using those bullets.
With that said, your 30.4gr charge would be pretty mild and much lower velocity in my rifle, most of the year here. For about 9 months out of the year I was using 32.8gr of Lever for that load, and then using a lower charge weight for my "summer load" to achieve the same velocity. Temps here are pretty mild though, and if you're into hot weather already that'd be a big part of the difference, along with maybe chamber and brass differences. I've seen 50+ fps difference in the same charge on the same day between brass brands.
At the end of the day, I recommend finding a safe max velocity (Lever works best when pushed hard, lowest SDs and best accuracy) and then adjusting the powder charge to match that velocity for hotter or colder temps, different brass, etc. I've achieved pretty consistent results with Lever that way. In fact, for load development with Lever any more I just find that safe max (i.e. as hot as I can push it with good brass life) and then tune OAL for accuracy. That keeps it simple and easy.
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