Any chance your second safety rolled forward? This may happen during or after sighting in, as recoil seems to move it forward a little. Happened to me once in practice. Got to get in the habit of checking to see if it is completely rearward, or jamming it with a plastic tie or something. I tried loc tite once, but had a hard time getting my bolt apart with only hand pressure. Won't do that again.

Another idea is turn your rifle upside down when cleaning the chamber, so grit doesn't fall into the trigger group.

Please let us know if it was a safety or trigger problem when you get to the bottom of it. Where the primers struck?

I'm very happy with my Elite.