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

[DeNinny]

I’m not following those numbers. I’m not sure what you’re saying, so it might just be me.

The deeper the bolt face, the longer the headspace.

Grendel bolts should be no deeper than .136”, but can be .003” shallower (.133”). Chambering will be more difficult and not repeatable under some conditions if you go less than .133”.

Chambering will be easier with deeper than .136” (out of spec), but then the case web won’t be supported and you can have things like this.

Most bolts I’ve measured were either .136” or .135”, but I do recall one that was .137” that probably shouldn’t have left the vendor.

Once you start exceeding the dimensions, tolerance stacking can occur and create unsafe headspace.

I am aligning to your thinking. Basically I was evaluating the difference in how much a round, with an out of spec deep bolt and with excessive headspace, would add to the unsupported side wall area. 0.138" was your out of spec condition, and 0.133" was your in spec condition. This means at least 0.005" of case depth is being exposed to unsupported wall area, in addition to what is already exposed by the feed cone. I hope this makes sense now.

And then you could even add the headspace excess to it.

What I'm trying to do here is get a rough quantification of the importance of excessive headspace being the issue.