Pressure X Burn Rate= Velocity

If you are working up a book load and are 200 fps below book Velocity you can safely add more powder to get to book Velocity.

Yes different powder lots may have a slightly different Burn Rate however the difference effects Velocity far more than pressure. If one stops at the given Velocity for a book load given any lot of powder your pressures will be very close to book pressures.

Shod


The 6.5 Swede, Before Gay Was Ok