Hope you get those vision issues straightened out, that's no fun.
I am using Lapua brass, among others. I don't know the water capacity though and may not get a chance to measure for a bit. I can say that while the Lapua brass has been the most consistent for me, it doesn't necessarily last the longest or handle the warmest loads; some of the other brands have done better in that regard in my rifle. (Actually, that has held true for me in both the 243 LBC and the 6.5 Grendel.) I don't push it too hard though, other than determining max and backing off from there.
If you're using the same Lapua brass and BHW barrels, I'd think your velocity capabilities should be very similar to mine, taking the barrel lengths into account. Mine is a 24", although I'll be finishing a 20" soon to compare numbers. I'd be very surprised if your 22" was more than ~75 fps slower than mine though, and more likely 30-40 fps. Do you know what velocity you're getting from 29.5gr of Lever with that 105?
Also - make sure you're not bumping the case shoulders back too much, no more than .004" or so. Excessive shoulder bump can show false pressure signs; even .010" bump can do that. FYI my new Lapua brass had the shoulders .010" back from a Go gauge, so it had a tendency to show some false pressure signs on the first firing that don't show up after that with the same loads. It did that in my LBC and the Grendel.
On the build details, the main thing I was wondering is how tight/secure your barrel is in the upper; if it's a thermo fit or shimmed and glued, or just set into a typical slightly loose fit? It's been a bit since I've assembled an Aero upper, but IIRC they were a pretty standard slip fit with a normal barrel extension, and could benefit from shimming and Loctite, or at least Loctite. (Use green 680 or 620, not just blue 242 or 243.) That can help with accuracy a bit, although it won't turn 1.5" groups into 0.5" groups.
A comment on shooting position and ergonomics with ARs - a more vertical grip is helpful for prone or bench shooting, and works just as well everywhere else. I prefer the Magpul K2 grip. The standard A2 mil-spec grip is terrible IMO; that's one of the first things I change out.
Along with the vertical grip, moving your thumb to the palm side of the grip (instead of wrapping around) and only pulling straight back with your fingers helps. Of course that goes along with setting up straight behind the rifle instead of bladed to one side.
With all of that done correctly, to me an AR feels just as natural as a good bolt gun for prone shooting, and better than a typical hunting stock bolt action.
Last edited by Yondering; 12/09/19.
