18" douglas SPR barrel, unsuppressed.

8208xbr, PPU brass, 2.255 OAL, 77gr nosler CC, 80F ambient

23.0----2555 AV
23.2----2581 AV
23.4----2624 AV

That douglas is not particularly fast, but might be typical for an 18".

I did not go higher as IMR/hogdon has not published 5.56-only data and 8208 shows pretty high pressures in load books compared to similar velocities with other powders. I was not seeing pressure signs, however.

Got some very good groups out of it, but not enough to statistically prove to me that it was worth loading over the TAC I have been using.

I would like to spend some more time with 8208 as I like the idea of the temp stability, but TAC has been very good as far as ball powders go, has given single digit SDs, high velocities, and has been very forgiving with pressure. Might be just a hair slower burn rate. It's also something like $6 less a pound...