I am fairly sure the Speer manual is #12. A friend told me about 2400 and just a few weeks after I found some at a LGS, so I scarfed it up, upon looking in my reloading manual it said * use magnum primer. I asked him he said he didn't. I loaded up a half dozen with Federal SPP and shot them over my chrono, not close to what the book said and looked like half the powder didn't burn. I don't have any small pistol magnum primers, but I do have the stupid Remington 61/2 small rifle primers that were made for 22 hornet, I tried them with the same powder charge and got much closer to book speeds and less unburnt powder. These are the kind of things that give new reloaders fits. I have been loading since about 1994, and with this manual saying use a magnum primer, the next saying don't use one. Thanks for all the replies.