The only thing I've done to my 338 RUM is turn the trigger pull down to 3.5 lbs. The rifle will shoot a 250gr Serria bullet at 2998 fps with 95 gr of RL25 max load will shoot a 225 gr bullet at 3100 fps with 98gr of RL25 max load and it will shoot a 200 gr bullet at 3150 fps with 99gr of RL25 Max load. This is how fast I shoot these bullets they are all at MAX, I chronographed them with a Pact chronograph.