Been running 26.0grn. LeveRevolution, Remington Brass, Fed. 205M's in my 16" AR.
The last 5 I fired went into 7/8" at 100 yards (3 were in 3/8'). Rolling 2700 and change out of my 16" Black Hole Barrel.
It's a Wylde chamber, so if you're running a bolt gun, I'd start a couple grains under that.