Another Trail boss question

[cr500]

I am after the quiestest subsonic load in a non suppressed 300 whisper rifle. I read other posts about trail boss but have a few more queries. Will I be able to get 180gn bullets up to 1040 fps with this powder? Will I run out of case volume or will pressure be too high to get up to 1040 fps with 180gn bullets?
Any other recommendations for the fast burning, low density pistol powders, purely for quiet subsonic loads.