Congrats.
Now you just may realize something I've been teaching people forever. Mechanically there's no difference in 100-300-500-1,000 or beyond.
Have faith in yourself, your equipment, your ammo, know your drops and windage and you can still get it done to the limits of your equipment.
It's having precision equipment that makes the difference beyond 600 and it looks like you are well equipped so the rest is practice, practice, note keeping, and more practice.