The RCBS AR Small Base Die Set for .243 Winchester (RCBS part no. 11407) pairs a small base sizer die with a taper crimp seater die to keep your semi-auto reloads chambering reliably. The small base sizer resizes fired cases down slightly more than a standard full-length die, correcting the case expansion common in gas-operated AR-platform rifles, while the taper crimp seater seats the bullet and applies a clean, uniform crimp in one step. Machined to tight tolerances, this two-die set is aimed at AR shooters who want dependable feeding and chambering from their handloads.

Key Specifications

• The Small Base Sizer Die resizes cases to correct the extra case expansion typical of gas-operated AR-platform rifles.
• The included Taper Crimp Seater Die seats the bullet and applies a uniform taper crimp in a single step.
• The set is chambered specifically for .243 Winchester.
• Helps reloaded cases chamber and extract reliably in gas-operated actions.

Frequently Asked Questions

Why use a small base die for AR-platform rifles? Small base dies resize the case body slightly smaller than standard full-length dies, which corrects the extra expansion that gas-operated actions can cause and helps reloaded cases chamber and extract reliably.

Does this set include a crimp die? Yes, the Taper Crimp Seater Die seats the bullet and applies the crimp in the same step, so a separate crimping die isn’t needed.

Buy the RCBS AR Small Base Die Set .243 Winchester

Keep your semi-auto .243 Winchester reloads chambering and extracting the way they should with this two-die set. Order it from our Lubbock, Texas gun shop, where our gunsmithing tools lineup covers everything from sizing dies to case prep gear, with fast shipping to your door.