Case Priming

Case Priming is a critical handloading operation because in order for ammunition to perform efficiently, consistent powder ignition is mandatory. This step must be completed before adding new powder, so your gun’s propellant powder is contained at the bottom of the case.

Primers are small metal-clad cups that hold priming mixture, an anvil and a foiling disc. Primers create a spark when hit with the firing pin.

First, check to make certain you have the right size. Primers for U.S. cartridges come in two diameters — large (0.210”) and small (0.175”) — and two general types — rifle and pistol. Rifle primers have more rigid cups and a hotter flash than pistol primers.

1. Clean the Primer Pocket – Check for any powder and primer residue that may have contaminated the primer pocket, and use the Primer Pocket Cleaner to remove it.
2. Chamfer any Military Crimp from the Primer Pocket – Never prime military cases without first removing the crimped area that held military primers in place with the Primer Pocket Chamfering Tool.
3. Primer Seating – To push primers into the primer pocket of your cartridge case, use the Co-Ax® Press, our multipurpose handloading machine, or the Co-Ax Primer Seater, a tool dedicated exclusively for priming. Insert each primer, open side up, into the priming tool’s cup. (Before handling primers, always wash your hands to remove any oils or lubricant. Powder-free latex medical gloves can help you safely handle primers with greater dexterity.)
4. Separate any cases with primer pockets that are too loose to hold a primer securely. This situation can occasionally occur if the previous load fired with that cartridge case was too “hot.”

As you become more proficient in reloading, you will fine-tune your own process based on your tools/equipment, the type of shooting you do, the guns you reload for and the goals you have for your handloaded ammunition. We suggest that you continue to read, learn and understand various methods so that you can find the system that works best for your needs.

Suggested Further Reading

• Designing and Forming Custom Cartridges for Rifles and Handguns, Ken Howell
• Reloading: Priming for Success, Tom McHale
• Rifle Round Reloading Guide, Kevin Wilson
• Seating Primers, Roy Hill
• Shooter’s Bible Guide to Handloading: a Comprehensive Reference for Responsible and Reliable Reloading, Wayne van Zwoll
• Three Simple Ways to Complete the Priming Step of Reloading , Tom McHale