Small pistol and rifle primers utilize a cup 0.175" in diameter, while large pistol and rifle primers measure 0.210" across. Large rifle primers are 0.008" thicker than a large pistol primer.

As mentioned, 9mm handgun cartridges use small pistol primers. Small primers have a diameter of 0.175 inches while large primers measure 0.210 inches. John B. Snow Rifle Primers Versus Pistol Primers.