I have two cases that blew at the rim, I had loaded them a couple of years ago for my FAL. 43.5 Varget, 168 fmjbt. once fired LC brass, Win primer. Have shot them when I first loaded them no problem. The first one blew in my R25. I took some of them down and everything looked good. I shot some in my FAL blew another one. tore 10 more down everything looks fine. I checked head space and went over the brass from top to bottom. I guess some of the brass is bad even if it looks good. No pressure signs except the blown rim, primer looks good not flat. Could it be slam fireing? I am not going to shoot anymore of them, It has got me scared.