What was your regulating load? Folks have reported very good success with the 75% rule.

Start with your regulating load and use the same powder charge but drop the bullet to 75% i.e. if regulated with 60 gr. of RL-15 and 400 gr. bullet use 60 gr. of RL-15 and a 300 gr. bullet.

You can also use the same bullet weight but reduce the powder charge down to 75% so in the case above it would be a400 gr. bullet with 45 gr. of RL-15.

For some folks the 75% rule has been spot on and for some it has required a little bit of fine tuning.

Eric