With your 26" barrel you should be able to comfortably get the velocity to around 2910. Then you can try 1000 yards...
Don't know if you have the case capacity though.
Not with N150 unfortunately. If I used a drop tube I could probably fit a couple more tenths...or if I went to Lapua or LC brass I could probably get over 25gr fairly easily. Starline brass is thick, and I'm handicapping myself with it.
I don't think N150 is going to be optimal for really squeezing all of the potential velocity out of a .223 anyway. I just wanted to test it out since I was sitting on a lot of it, and my old stand-by .223 powder (Reloader 15) wasn't really impressive with this bullet.
Fortunately for me, 99% of my shooting is at 650 yards and in.