I don't understand what e-book you're getting your information from, but Big rifle and enormous pistol primers are certainly not interchangeable. I'd a product sales staff man or woman inform me Once i ask what number of primers could I purchase….the reaction was…”All of these If you need them.” https://22ammo1000rounds88396.ambien-blog.com/17138054/small-pistol-primers-gunbroker-no-further-a-mystery