I've been using "magnum" small pistol primers in my 9MM's for years. I have a stock of them, and don't shoot .357 mag anymore, so I use them for 9MM. When they run out, I'll go to my regular small pistol primers. Accuracy, velocity, and all other characteristics are normal in all loads, but these are with very moderate, low to mid range power, target loads. I am not pushing the limits of the 9MM pressure. These are punching paper rounds only.