+1 on Blammer's and Chargar's tips for safely decapping live primers. I would add, wear safety glasses AND close your eyes. NEVER do it with military crimped-in primers. I have decapped many live primers with no surprises. I don't reuse the primers because disassembling a misfired cartridge is a PITA, especially with pistol rounds as it's hard to come to grips (pun intended) with the bullet/boolit.