24.0gr to 24.5gr depending on your specific gun.
24.0gr is enough and will shoot well in nearly every gun. Basically better than most shooters.
24.5gr is hotter and better for 600yd if your gun has a favorable node at that mark and you don't mind losing 1-2 reloads on your brass.
If you're not sure what a "node" is, look into Optimal Charge Weight, OCW load development. I beleive this is what EddieCoyle teaches in his classes.
The short version is your barrel has a harmonic and you don't want the bullet exiting when your barrel is deflecting the most.
24.0gr is enough and will shoot well in nearly every gun. Basically better than most shooters.
24.5gr is hotter and better for 600yd if your gun has a favorable node at that mark and you don't mind losing 1-2 reloads on your brass.
If you're not sure what a "node" is, look into Optimal Charge Weight, OCW load development. I beleive this is what EddieCoyle teaches in his classes.
The short version is your barrel has a harmonic and you don't want the bullet exiting when your barrel is deflecting the most.