I had a partial case head separation using a 1.8oz buffer

[stonehog]

Please place any Lapua brass you don’t want on the EE.

I’ve been loading Lapua brass in Grendel since 2009. It’s the best brass there is for the cartridge in my experience.

For someone to get a case failure on first firing with a load well-within limits indicates a problem somewhere else.

I’m suspecting the feeding cone not supporting the case. Brass is inherently soft, so it will push around even with low pressures. When unsupported, it will yield like this.

stonehog, was your extractor still intact?

Yes - the extractor was in good shape, but the bolt was out of spec after this firing per seating the no-go gauge.