RCBS 11131 Small Base Sizer Die for .223 Remington

The RCBS 11131 Small Base Sizer Die is designed for reloading .223 Remington bottleneck cases used in firearms with tight chambers, including many semi-automatic, pump-action, and lever-action rifles. This specialized sizing die reduces the case body and shoulder slightly more than a standard full-length sizing die, helping improve chambering reliability when cases have been fired in different firearms or need additional sizing for dependable cycling. It is a practical choice for reloaders seeking consistent case preparation for compatible .223 Remington ammunition.
The small base sizing function brings cases below SAAMI minimum dimensions in the body and shoulder areas, reducing them by a few thousandths of an inch as needed. This additional sizing can help address chambering issues that may occur with cases fired in semi-automatic platforms. The die also includes a decapping function to remove spent primers during the sizing process, allowing case preparation and primer removal to be completed in one operation. Follow established reloading procedures and consult a current loading manual for proper setup, die adjustment, component selection, and safe operating practices.
The RCBS 11131 is a single small base sizer die intended for .223 Remington reloading applications. It is not recommended for ammunition intended for bolt-action rifles, where the tighter sizing may result in unnecessary case working and reduced case life. As with all reloading equipment, inspect cases before processing and verify that resized cases chamber correctly in the firearm for which the ammunition is prepared. RCBS is recognized for producing durable, precision-oriented reloading equipment, and this die provides a focused solution for reloaders who require additional control over case dimensions in tight-chambering firearms.

Features:

• Type: Small Base Sizer Die

• Caliber: .223 Remington

• Die Type: Sizer Die

• Function: Resizes the case body and shoulder below SAAMI minimums

• Decapping: Removes spent primers during sizing

• Application: Designed for tight-chambering semi-automatic, pump-action, and lever-action firearms

• Compatibility Note: Not recommended for ammunition used in bolt-action rifles

• In Set: 1 die