28 Nos Flat Primers

[Rflshootr]

Checked and verified when it was trued. Even if I jam bullets it still does it. Only rifle I've ever seen do it that checked out correctly.
It does it to all primer brands.

Cheers.

Then the only other thing that I can think of that would do it, other than excessive pressure, is the chamfer around the primer pocket letting the primer flow. I'd compare the chamfer on the Norma against the other brands.
Just curious, have you ever run a pressure trace on that rifle to see where it spikes?

 

[Tiny Tim]

I have a Savage that does the same thing, starting loads to max. Different primers do the same. Haven't tried different brass. Hasn't been a problem, but I'm not typically a "hot rodder" either.

 

[FullCurl8]

It's not a 28 Nosler known problem.
Is your rifle a custom build?