Hornady Seventh Edition has 300 whisper info!
 

:nanabang:

they list seperate loading for 110 to 190 grain bullets.

No, Subsonic information :frown: but this was all out of 10 inch 1:10 T/C Contender barrel for work up for hunting/Steel shooting - They used Remington .221 fireball cases necked up and noted only valid for SSK or T/C barrels with True Jones' chamber.