RCBS Neck Expander Plug Features The RCBS Neck Expander Plug is manufactured to work as a direct replacement part for the RCBS Neck Expander Die letting reloaders refresh a worn component without replacing the entire die. Sized for .358 caliber this plug is part of a broader range of available dimensions that RCBS offers including .224 .227 .264 .308 .309 .310 .321 and .323 among others covering most popular cast bullet calibers. The design allows the reloader to expand the case neck and flare the case mouth in one single step streamlining what is otherwise a multi-stage process. This efficiency matters most to reloaders processing large batches of cast bullet ammunition. For cast bullet reloading specifically proper neck expansion is one of the most critical steps in the entire process directly affecting how well the bullet seats and how consistently it releases from the case under pressure. RCBS designed this plug with that critical step in mind prioritizing the dimensional accuracy needed for a cast bullet to seat without being damaged or deformed. Reloaders who cast their own bullets rely on precisely sized components like this to maintain accuracy and consistency across their loads. Handloaders working in .358 caliber will find the RCBS Neck Expander Plug a dependable purpose-built replacement component for their reloading setup. RCBS Neck Expander Plug Specifications Manufacturer: RCBS Caliber: .358 Cal Type: Neck Expander Plug Available At: GrabAGun