Pressure is effected by:
Powder burning speed and quantity
Bullet weight
Seating depth (Oal)
Bore Diameter
Bore friction (smoothness, or lack thereof)
Groove depth
Bullet bearing surface area
Bullet (or jacket) hardness
Core hardness
Primer brisance
Case thickness (capacity)
Expansion Ratio
Uhhhhh...... IOW, unless you have access to a ballistics lab, follow the manual.
