So,a friend gave me a box of Winchester brass. He'd bought the ammo new at Walmart and gave me the once fired brass when he was done. This is where it got weird. I was trying a new load with a Nosler bt bullet and started at the low end of the powder range in their manual. I did have to seat the bullet a little deeper than they did as the OAL they listed had the bullet jammed in the rifling. The primer pockets felt tight when priming then. When I shot the box of 20, I had two leaking primers which it's never seen before. I was pretty concerned but didn't see any signs of high pressure or anything which I thought was odd. I find a load with another bullet that worked well and went to load these a second time. I found 19 out of 20 to have loose primer pockets. I scrapped those and kept the one that was tight. I checked inside the case with a paper clip and didn't feel any sign of case separation. When I shot it, I ejected it only to find a crack at the bottom of the case with case separation happening. Something else I've never experienced. The other 20 pieces of Remington bra I've been using are holding up well and haven't had any issues. Was this likely a bad batch of brass or was something else going on?