Belted Cartridges after adjustable gas block

[badmoon692008]

Alright, I'm officially running out of ideas... I had issues with cartridges getting belted, and the gun was ejecting at about 1:00, so I figured I was overgassed. Got to the range today with a new adjustable gas block, and the first two rounds I shot that didn't cycle (because the gas block was turned all the way in) still had a belted look to them and I can feel a ridge. Below the belt line there's no marks that indicate the brass is supported at all, but above the belt line you can clearly mild scraping/carbon deposits from the barrel. The gun is ejecting at about 3:00 now, so at least that improved. Is this normal? Any ideas? Am I missing something easy?

[kmon]

Sounds like a headspace issue if I read it right

[badmoon692008]

It's a matched barrel and bolt from PF. I'm assuming that's something they check?

[ricsmall]

Do you have a mic or caliper to measure the area in question and compare it to saami specs? They look fine in picture but I'm not touching them. If there is a problem contact mark. I'm sure he'll have an answer.

Richard

[badmoon692008]

Above and below the bulge in the case the diameter is 11.15mm. The bulge is 11.24mm. The bulge is approximately 7mm above the base of the case

[badmoon692008]

Are these new cases? Is there any chance they were fired in your rifle with the original gas block?

Brand new factory Hornady 123 Amax

[badmoon692008]

Above and below the bulge in the case the diameter is 11.15mm. The bulge is 11.24mm. The bulge is approximately 7mm above the base of the case

So after looking at the spec I see that I'm still under the chamber dimension of 11.242. So is this just normal and I shouldn't worry about it and it'll clear up with resizing/firing? I'll have to measure a few of the other cases that cycled to see what they measure out to.

[LRRPF52]

Yours look normal to me. Just clean and re-size them with Spray-on lube, like Hornady's One-Shot. An expanded base or "belted" case is unusable after firing. In Volume I, Page 14, we have a picture of what a belted case looks like from early unlocking.



Here's another one:

[lead chucker]

Cool where did y'all get the magnum grendel? Just kidding

[motoxxx_ryder]

some of mine had belts, the sizing die took them right now.

[Kikn]

Looks normal to me to. My brass looks just like that after firing, it reloads just fine to.

[badmoon692008]

Looks normal to me to. My brass looks just like that after firing, it reloads just fine to.

Sounds good, that's all I needed to hear!

[NugginFutz]

I wouldn't call that belting, so much as a shiny band. Many of my cases show this same attribute, but a quick check with a ball micrometer revealed no thinning of the case walls.

There's a rumor going around that new Hornady 123 Amax has a "pot bellied" case, and that could explain your cases. The guy at ARP says because he cut his 264 LBC chambers so tight, the "belted" AMax were sticking and that is why he no longer makes 264LBC barrels. If true, the unfired cases should also have the "belt" - not that it matters. Any SAAMI spec'd chamber would digest such a bullet with no issue.

Like others have said, it appears you are good to go.

[ricsmall]

Post removed. Irrelevant to op's topic.

Richard