Help me with these case heads

[Canuck1977]

Hi all,

Please help me see signs of pressure. Primers look ok... but I see some ejector marks... shot these in a 2015 AIAT 308win 20" barrel in 1-12". Velocities are mild in the 2600 with 168ge SMK and Varget.

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[MakeSawdust]

What was the powder charge? Sometimes "pressure signs" show themselves for other reasons. Typically a machining or mechanical issue with the gun. Also, what was the distance from the lands? Do cases from factory ammo look like that? You definitely have some pretty significant ejector marks on those case heads. Hopefully you can get to the bottom of the issue and move on.

 

[Canuck1977]

There are some ejector marks on factory FGMM 168gr. Bolt lift is normal... smooth ejection. Charge of the reloads was 44gr of varget and bullet 0.030" off the lands.

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[sirhrmechanic]

I'd go with some roughness on the bolt face. The primers look great. Perhaps a barely-perceptible amount of flattening, but no extrusion around the firing pin and basically looking good. I would not have had any concerns about those rounds as long as they ejected well and didn't give other signs of an overload.

Are they hard to re-size? Oversize chamber? Might try getting the bullets a bit closer to the lands... if your magazine/feed allows.

Cheers,

Sirhr

 

[MakeSawdust]

Check your bolt face for a small burr or irregularity around the ejector. It is possible that could be causing what you are seeing. Let us know what you come up with.

 

[Canuck1977]

Thanks for the comments. Neck sizing is easy. I did fired those cases 3 times and did a full size on them. Was a little harder but still within what I experienced before. The rifle shoots 0.2 MOA with FGMM and this handload... primer pockets are still tight after 6 firing.. the only issue I have with the rifle is with the extractor. AI has been made aware of this issue. I'll have them look at the ejector area for burrs.

 

[Milo 2.5]

Just chamber a loaded rd, do not fire, eject and see if brass is marred, your plunger may not be retracting enough.

 

[Sendit6.5]

Just chamber a loaded rd, do not fire, eject and see if brass is marred, your plunger may not be retracting enough.

^^This^^

I think there's something up with your ejector. I can't remember ever having ejector marks without having some obvious primer signs first; and your primers look terrific.


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[Timo Turl]

My 2015 AT does exactly the same thing even on unifired loads. I've trying flushing out the plunger to no avail. Doesn't appear to be any roughness on the bolt. Curious what you find out.