Here's one for you guys...
Went to the mountains with my wife and boy and shot a bit. I put about 100rds of store bought (not reloads) .38spl and .357mag through my S&W Model 66-4. As usual, I saved my brass to reload. I get back home and sorted them only to discover that out of the box of 50 .38spl, I had about 7-8 split cases... right in the middle lengthwise. Primers are not bulged.
Now this is the first time I have shot this gun (was my dad's until he passed) and it was given to him used. The gun is in mint condition and looks to either have been shot VERY little or not at all (a clue perhaps?).
I'm thinking that either:
1) Overly hot batch of .38spl (didn't feel like it) and over pressure split case (but not bulge the primer caps?)
2) I had a bad batch of .38spl with brass walls of the case too thin
3) I have a cylinder out of spec (wish I had paid attention as I unloaded to confirm this and I had an odd number of rounds to just do the math for logical deduction)
4) Combination of the above
Thoughts?