Having had the opportunity to run the 90s now for a bit, I'm guessing that with a 32" barrel throated out to about .200" freebore or so, it would be relatively easy to push the 90s in the neighborhood of 3000 fps
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Running with ~.240 freebore and 31-inches, I found 2,915 fps the limit with the 90gn VLD and 50-75 fps less with the LRBT. That was with Re15. VarGet saw pressure problems 50 fps down and Viht N550 might have produced a bit more velocity, but I could never get the groups small enough with it, or consistently small ES values.
Remember too, this was in the British Isles where 30-deg C air temperatures in the shade are classed as 'heatwave'. Even so, I had to keep the ammo in a cooler bag on the occasional warmer day as Re15 is not nearly as temperature insensitive as its makers claim.
We now have Reload Swiss RS52 here, a high-energy powder with a burning speed close to that of Re15, but with Nitrochemie's patented EI deterrents technology that flattens / extends the early peak curve in the pressure trace - think a faster burning version of Alliant Re17 which is RS52's slower burning sibling in the Nitrochemie Reload Swiss range (RS60 in Europe). I think that'll get MVs up, but not to 3,000, and it's no use anyway if the groups aren't under 0.4-MOA and ES values at 20 or below. There are those on this forum who claim Re17 is badly heat affected. If so, I would expect RS52 to behave similarly, so back to the Re15 problem.
FWIW, I have a friend, GB FTR league champion more than once who's also a 223 fan (but won't ever, never ever, consider it for league shooting) who runs things a wee bit (like LOT) hotter than I ever would. He doesn't like 90s but has had some fantastic long-range scores with the 80.5 Berger at 3,100 fps or so. I was with him load testing one day and he got the lighter bullet to 3,200 fps from 30 inches of barrel. 1-MOA groups and a one shot dump the case sort of load mind you, but run that through an ME calculator and that way over the top load works out at 1,830.85 ft/lb. Convert that to fps with a 90gn bullet and you get 3,026 fps, barely above your target speed.