Do you know the process of making gun primers — how explosive elements are placed into tiny cups? Watch this video, filmed in a Federal ammunition plant. The process begins with 1000 empty primer cups being loaded into trays by vibrating (0:05 mark). Although much of the process has been automated, production workers still play a major role in applying a green, pastelike charging compound inside hundreds of primer cups. You can see a factory worker “charging the primers” with the priming compounds at the 0:17 time-mark. After the cups have been filled, the plate of anvils and cups “mates” up (0:40). The primers are then removed from trays and examined. The Shooting Times website has a great article on primers. This authoritative article from Shooting Times explains the finer points of primer construction and design. The author corrects some common misconceptions about primers, and reveals some little known facts. Here are a few highlights: Size matters
Useful Trivia – although Small Rifle primers and Small Pistols have the same depth specification, Large Rifle primers and Large Pistols do not. The pocket of a Large Pistol is shallower than that of a Large Rifle primer, by 0.008 to 0.09 inch. Magnum Primers
There are two ways of making a Magnum primer: either add more of the standard chemical mixture to give a longer burning flame, or change the mix for one with a more aggressive burn characteristic. CCI used to use the first option for Magnum Rifle primers prior to 1989. After that, we switched over to a mix optimized specifically for spherical propulants that produced a 24% boost in flame temperature and 16% boost in gas. Foiled Again
The paper disk is usually placed between the anvil of the component primer and the priming mixture. It’s called “foil-paper” not because it is made of foil, but because it replaces metal foil that was used to seal the early percussion caps. This little disk is purely a convenience for manufacturing. Wet primer pellets have a smaller diameter than the inside diameter when they are inserted into the cup and must be compressed to reach their correct diameter and height. The wet mix would adhere to the compaction pins without the foil paper and cause the assembly process to be clogged. Boyd Allen found the video for the full story on ShootingTimes.com. We welcome reader submissions.
