There 2 ways for you to drop the velocity
1. is remove the power spring and cut it off about 1/8 of an inch
this will drop the velocity down about 10-20fps, you can repeat until you get the the velocity you want
2. another option is a get an inline regulator, rap4 has it. the AG1 regulator let you set down the pressure and will bring down the velocity.
Oh. keep in mind that if you are using co2, and if it is a cold day, your velocity will be higher than warm weather