So my son and me are shooting 22 pistols (ruger MKII's) indoors last week, have been on vacation since - and the darndest thing happend. One of the rounds had a case failure - 2 spots on the rim blew completely out. Made a funny pop and some smoke and everybody stops & looks and says "what was that??" The ammo was Federal and was old, probably at least 20 years old. Now I've shot my share of .22 rimfire over the years, but never seen that. Certainly, this was caused by the age of the ammo, but still, never seen this. The gun is in perfect shape, before & after. Just found it odd, that's all. I told my son - take that brick of ammo back to your pal and tell him to take it to the local police for disposal. They do that around here.. By the way, the ammo looked perfect on the outside. Must have corroded from the inside. Just wanted to pass this along and see if anybody else has seen this kind of thing. Enjoy Mike