Curious, never seen this before

[skibbyshot]

Based on others comments, have you checked your bolt face for damage?

 

[cloverleafs]

Are you absolutely sure that they are both your cases? The firing pin mark on the blown out one is dead center, the other one is very slightly off. Or is that just the picture or my eyes? Could you have picked up brass from another rifle?

 

[mdvctry]

Wow! Thanks for sharing the pics and all the comments sharing your experiences with WLRM primers, it's good information. I'm learning a lot in this forum.