For 9mm ammunition, you need to use *smaller pistol primers*. Here are several specific recommendations and things to consider: ### Primer Style - *Little Pistol Primer*: This can be the typical primer useful for reloading 9mm ammo. Makes like CCI, Federal, Winchester, and Remington all develop trusted smaller pistol primers. https://winchester200primersinsto79023.yomoblog.com/37806890/look-at-highly-regarded-makes-noted-for-quality-and-reliability