MEC Primer Cup

The MEC Primer Cup (model 326) is an essential replacement component for reloaders who operate Mayville Engineering Co. progressive presses, including the 600 Jr., 700 Versamc, and Sizemaster platforms. Whether you're managing a high-volume handloading operation or maintaining consistent ammunition quality for competition or field use, this primer cup assembly keeps your reloading session running without costly downtime. As any experienced reloader knows, primer cup wear or damage can halt production mid-session—having a spare on hand eliminates unnecessary interruption.

Engineered by Mayville Engineering Co., the primer cup is a precision-molded component that seats and manages primer orientation within the press's primer feed system. Its compact footprint (3.7 × 1.15 × 4.45 inches) and lightweight design (0.13 lbs) make it a low-cost consumable that should be stocked as part of any serious reloader's maintenance kit. The cup material and fit tolerance are calibrated to work seamlessly with MEC's proven press geometry, ensuring reliable primer pickup and consistent ignition performance across all supported calibers. Replacement is straightforward—no specialized tools or gunsmithing required.

Competitive shooters, precision rifle enthusiasts, and high-volume reloaders benefit most from stocking this part. If you operate a Mayville 600 Jr., 700 Versamc, or Sizemaster, maintaining a backup primer cup ensures you're never sidelined by a broken component during critical loading sessions. This part is compatible exclusively with the above MEC press models—verify your equipment before ordering. At this price point, purchasing a spare represents smart preventive maintenance and pays for itself the first time it prevents session downtime.