28 Nos Flat Primers

[Hikinghunter]

All the primers I pop out of 28nos brass look like this. Factory ammo, reloads from the lower end to the top, doesn't seem to matter.

My 280AI doesn't do this. Is this just a 28nos thing? Wondering if this rifle needs to go back to the factory for a check-up.

 

[fseaman]

Have you measured fired brass vs resized?

If the primers are popping out something not right with a length somewhere.

 

[Hikinghunter]

Have you measured fired brass vs resized?

If the primers are popping out something not right with a length somewhere.

Brass shoulder isn't moving forward, or at least not more than a thou (my calipers are only so sensitive). Using Peterson brass. The primers are not loose or falling out, I'm removing them with a depriming tool. They are just flat, with that "nail head" look.

 

[fseaman]

Please show the firing pin side.

Please show the champher on your primer pockets.

What is your reload recipe?

 

[tomcat818]

Are your primers being seated properly: slightly below flush with the base? Peterson brass has tight primer pockets so if your not seating primers below flush I don't think the firing pin strike would have enough force to seat it leading to the primer being partially extruded when brass starts to flow.

 

[Hikinghunter]

Please show the firing pin side.

Please show the champher on your primer pockets.

What is your reload recipe

Keep in mind that it's flattening primers for all factory ammo (nosler, hornady, Pendleton). So I don't think it's a load issue here. I'm wondering if this is just a thing with 28 nos. But here's a photo some fired handloads anyway.

No noticeable cratering.

Peterson Brass
WLRM primers
175gr Berger Elite Hunters
Retumbo (77.5 to 81 grains, makes no difference in terms of primer flattening).

 

[Hikinghunter]

Yes

Are your primers being seated properly: slightly below flush with the base? Peterson brass has tight primer pockets so if your not seating primers below flush I don't think the firing pin strike would have enough force to seat it leading to the primer being partially extruded when brass starts to flow.

yes. I test every one of them on a flat surface. Again, the rifle flattens factory ammo primers too. It's not a handload issue.

 

[Mram10us]

Dumb question. Have you checked go, no-go gauges in rifle to verify headspace?

 

[tomcat818]

The primer second from left is super flat looks like over pressure the others have slight radius. If you have a camera with a flash take some in focus pictures (like below) of removed primers from factory next to handloads along with an unfired primer for comparison .

Also, what factory ammo? Nosler has a recall on their 28 Nosler ammo for exceeding max pressure.