The Auto Primer Tube is crafted for use with the RCBS Automatic Primer Feed, allowing primers to drop one at a time into the primer plug and sleeve. This design helps prevent misfires by eliminating the need for greasy fingers to handle primers, while the nylon primer pick-up ensures primers stay in place. With a capacity of 100 primers, this tube is compatible with the Rock Chucker II and Reloader Special Presses. Note: It is not suitable for use with the RC Supreme.