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

[lazyengineer]

Both of you are making assumptions.

Ninny,

You are assuming the quality and percentage of brass alloy is the same across manufacturers. Cartridge brass varies in quality and mix (Copper/Zinc). Here's an article from Accurateshooter.com that includes spectroscopy findings. Bottom line, thinner brass can be stronger.

Lazy,

Now, you are assuming both manufacturers cartridges went off in battery, and Lapua failed because it is inherently weaker. None of us know it was in or out of battery. Lapua's weakness, if any, is not common knowledge in the shooting community - quite the opposite. Shooters would quickly figure it out if there were more catastrophic Lapua failures such as this.

AR15s dont OOB, as the pin cannot contact the primer until the bolt is rotated into battery. In the 80,000 rounds i have fired in AR's, I have literally tested this hundreds of times in both grendel and 5.56, I'm not proud to say. Its not OOB, and fixating on that is denial of the obvious images in front of us.

There is a flat refusal to accept the obvious here - and it's not healthy. Eventually somebody is going to get hurt.