Using a small rifle primer in pistol ammunition is generally not advised. Here are some important points to think about: ### Variations in Layout 1. *Primer Composition*: Smaller rifle primers typically have a harder cup than small pistol primers, built to face up to better pressures connected to rifle cartridges. https://beckettbwqgy.blogolize.com/utilizing-a-tiny-rifle-primer-in-pistol-ammunition-is-generally-not-suggested-70641172