https://press.hornady.com/assets/sit...-60-62gr-1.pdf

Current Hdy data lists 60-62gr projos over H335 @ 20.1min - 22.9max for a high speed of 3000'/s (probably from a 20" or 24" bbl.)
If this is true you're already operating above recommended pressures, all other things being equal.

I used TAC for YEARS on prairie dogs - it was wonderfully accurate but I could never get my field experience to match the ballistic curves my load generated.
Finally I wound up with a really nice LabRadar unit which convinced me I was getting 300'/s short of published data for TAC.

I switched to H335 and MV matches published data now... and the calculated trajectories I carry as field notes are finally USEFUL. Accuracy didn't change a whit. Nearly all my rifles are 8 or 9 twist
but they have much longer barrels and are all bolt guns. H335 is the "go-to" powder for all military things 5.56. It should operate just fine in an AR.

I've never got much accuracy from FMJs in any weight but the ballistic tip Hdy and Nosler bullets in 50 and 68gr are superb over H335. So are Sierra Match Kings in 69gr - at least
out between 300 and 550 yards which is as far as I've tried them on PDs.