Bullet Design Parameters
A bullet length will be calculated that is compatible with the barrel twist rate.
Bullet weight will be estimated from the bullet length as either a standard round or flat nose bullet design .
The bullet body diameter will be calculated to allow the loaded case to have a neck diameter clearance in the chamber of at least 0.002". This will leave a clearance of 0.001" between the chamber wall and the loaded cartridge neck. ( Chamber neck diameter minus 0.002", less 2 time the cartridge neck thickness)
If the chamber free-bore is of a uniform diameter, then the front band diameter will be calculated as 0.0005" less than the free-bore diameter and the front band length calculated to reach the start of the lands.
If the chamber free-bore has a slight taper, then the front band diameter and length are calculated so that the front band touches the free-bore at the midpoint.
If the chamber is a revolver cylinder, then the front band diameter will be 0.0005" less than the throat diameter and the length will reach the start of the chamber leade that tapers down to the throat diameter.
The bullet In-Case length (bullet base to forward side of the crimp groove) will be calculated to match the cartridge case neck length.
The bullet bore-ride diameter will be the same as the bore diameter of the barrel.
If the "Calc. bore-ride length" option is checked, then the bore ride length will be calculated to reach to the end of the leade cone. (Start of the bore diameter in the barrel)
If the "Calc. to match cartridge O.A.L.",option is checked, then the bullet length will be calculated as cartridge O.A.L. minus cartridge trim-to length plus cartridge neck length.
If the "Calc. bullet length from bullet weight" option is checked, then the bullet length will be estimated as a either a standard round or flat nose bullet design.
All of the above initial critical dimension calculations may be edited before sending the values to the Cast Bullet Design Module.
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