Common Primer Issues
There are two main issues you may experience with primers. When ammunition is too hot or incorrect for your rifle you may see these while you are shooting.
Blown primers occur when the ammunition is too hot or strong for your rifle. If you experience this you should STOP SHOOTING THE AMMUNITION IMMEDIETLY. Continuing to fire rounds that are too hot for your rifles chamber can result in damage to your firearm.
Blown primers occur when a round over pressures upon firing in your rifle. The most common reason rounds tend to overpressure and blow the primer is remnants of cleaning solutions left in the chamber. Be sure you swab your rifles chamber after cleaning the barrel to be sure the chamber is free of all cleaning agents or liquids.
Pierced Primers occur when the firing pin is too sharp or even the wrong size for the primer used and it physically pushes a hole into the back of the primer, as seen below. This is a dangerous condition that allows blow back of gases from the firing cartridge to enter into your bolt and trigger. This can damage your rifle and cause further issues. It is most commonly seen in Small Rifle Primed Brass when your rifle has a medium or large firing pin. You can have your bolt bushed to remove the excess space around the firing pin to correct this issue, or you can simply try brass with Large Rifle primers to correct this issue.