POWLEY CALCULATOR   
                
    Case Length (inches)
     
    Selection Index
    Bullet Length (inches)
     
    <65 No IMR powder Slow enough to work
    Cartridge Length (inches)
     
    65-81 IMR 5010
    Water Capacity of Case(grains)
     
    81-91 IMR 4831 Reduced by 5%
    Bullet Diameter (inches)
     
    91-110 IMR 4350 or 4831
    Bullet Mass (grains)
     
    110-124 IMR 4320, 4895, or 4064
    Height of boattail (inches)
     
    125-144 IMR 3031
    Tail Diameter of boattail (inches)
     
    145-164 IMR 4198
    Barrel Length (inches)
     
    165-180 IMR 4227
    >180 No IMR Powder Fast Enough to work
    Powder Factor Selection
    If Powder Selection Index >145 change to .80
    Charge Weight Estimate (grains)
     
    Powder Selection Index
    Velocity Estimate (fps)