I made the big mistake a couple of years ago, of not keeping differant loading of same caliber ammo seperate.  The wife loads .44 mag for a carbine.  Her loads are way too hot for a pistol, and we all know it.  She always put her loads in a baggy and marked them with a Sharpie.  Over time the writing got rubbed off and one morning I grabbed them to go shooting with my pistol.  Got to the range and the first shot I knew something was not right, too much recoil, then hammer would not pull back.  Looked at gun, forced the hammer back and found cylinder was split.  I was lucky gun held togeather.
Sent gun to Ruger, they were able to straighten the frame and replace the cylender, and return the gun to me, along with a letter.  The letter stressed how close I came to losing my head.