RCBS Coated Neck Sizer Die Bushing .258

RCBS Coated Neck Sizer Die Bushing .258
Which bushing do I need for my cartridge? The simplest way to determine the correct bushing for Redding Type S and Competition die sets is as follows: Measure the average outside neck diameter of a finished cartridge (note, do not use an empty case) in inches. For a .308 Win cartridge, this is 8.57mm = .337 inches in our example calculation. (1 inch = 25.40mm). To ensure a tight fit of the bullet, 0.002 inches must now be subtracted. In our calculation example, that would be 0.337 inches minus 0.002 inches = 0.335 inches, and thus we need a .335 bushing. In some cases, a .336 bushing can also be used, but this depends on the elasticity of the case brass and the neck wall thickness, which can only be determined through trial and error. Redding states in its catalog that you should subtract 0.001 - 0.002 inches from the average outside neck diameter! Which bushing do I need for my cartridge? The simplest way to determine the correct bushing for Redding Type S and Competition die sets is as follows: Measure the average outside neck diameter of a finished cartridge (note, do not use an empty case) in inches. For a .308 Win cartridge, this is 8.57mm = .337 inches in our example calculation. (1 inch = 25.40mm). To ensure a tight fit of the bullet, 0.002 inches must now be subtracted. In our calculation example, that would be 0.337 inches minus 0.002 inches = 0.335 inches, and thus we need a .335 bushing. In some cases, a .336 bushing can also be used, but this depends on the elasticity of the case brass and the neck wall thickness, which can only be determined through trial and error. Redding states in its catalog that you should subtract 0.001 - 0.002 inches from the average outside neck diameter!