Marks on bullet. What is going on here?!?!

greenejc

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Dec 26, 2012
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Colorado, currently
Take a look at the video below. When I use my Hornady OAL gauge to push the bullet up to the lands I hit a good deal of resistance, if I push a little harder the bullet then slides up and stops (at what I assume is the lands). When I pull the bullet out it has these marks all the way around. This happens every time I try it. I have confirmed those marks are not from the case nor at any point during ejecting. Took it to the local gunsmith and he said “I don’t know, weird.” Thanks...He used a bore scope and didn’t note “anything out of the ordinary” but it seems like something is.

Anyone have any ideas. This is a Christensen ELR., chambered in 6.5 CM. The bullet is a 140gr Berger VLD Hunting.


Run it in to where it first meets resistance and measure the OAL. Its either going to be a bad throat or your lands are not as far out as you think and you're in them. I think ButterBean is right, though. If that's not the lands, then your throat is too tight and needs to be touched up. A standard finish reamer will clean it up with just a few passes.
 

woodnut

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roanoke,va.
I agree with ButterBean, looks like the chamber has one or more faults. I think you had the bore scoped to include the chamber, right? I know when I go to pull bullets from a case, I will see those marks, but you said the cases were very easy to slide the bullet in and out? If they were, they then would not be giving you correct COAL, so I question your comment on them "freely sliding in". But, the throat is likely the result of the reamer being the culprit, like ButterBean says.
 

codyadams

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Jan 7, 2015
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Southwest Wyoming
If you were team tight throat you win. Rifle on its way back from Christensen with a new barrel and re head spaced. Thanks for all the input.
Nice. Good to see a company standing behind their produce, and relatively quick turn around, a month and change for an inspection, then a rebarrel and return ship....let us know what you find with this tube please!
 

alarcher

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Sep 1, 2020
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AL
So I finally got around to shooting this rifle. The marks on the bullet are gone however I’m still getting major ejector swipe regardless of load. From 39 to 42.5 gr (h4350) in half grain increments. Velocities from 2603 to 2817 (increased linearly). The swipe looked the same on the 39 load as it did on the 42.5. Gunwerks (ADG) brass. Can’t figure this out. No other real pressure signs. Help!
 

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JemezDave

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Dec 5, 2018
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NM
Looks like the primer is cratered quite nicely(too hot). I would weigh that case compared to a hornady case or other. If the ADG case is significantly heavier that may be your problem due to reduced interior volume of the case itself. The reason I say that is on my 300 win mag I have a couple lots of "light" Norma brass. Norma also has a heavy brass listing in their load data for 300WM. The case weight difference is 215 grains for light cases and about 270 grains for heavy cases-you get the idea. There is a difference of 7 grains on the max charge using Norma 204 powder and a 200 grain Sierra MK bullet. The heavy cases use the lighter charge due to the reduced interior case volume. Make sure you're case length is in spec too.
 

7mmTikkaShooter

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Nov 3, 2015
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South Dakota
Yikes! Seems like you’ve had your share of bad luck with this barrel. I’m wondering if now you’re not running into a headspace issue? Maybe cycle a piece of virgin brass in and out of the chamber and see if your getting anything unusual. A go gauge if you have access to one would be ideal. This is still just a guess and may be no help. Must be frustrating. I hope you can get it figured out soon.
 

Tiny Tim

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Jan 26, 2015
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Is it possible to "slug" the bore? Perhaps the bore diameter is on the small side? Might explain pressure and low velocity.
 

Shane Lindsey

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Jul 13, 2010
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Chamber a round and remove it without firing. See if it produces swipe. could be head space as mentioned or just Christensen tight bore.

As it is a Christensen, it should have two ejector pins. I don’t see two pin marks in front of swipe. Looks like one on the left of it. Did you mark the swipe with a marker, as it may be hiding it.

Cratered primers are subjective also as it is usually a sloppy firing pin hole, especially as bad as that is. I get it on newer Rem bolts on factory ammo as well.
 

Patriot007

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Sep 14, 2019
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South Ga.
Yikes! Seems like you’ve had your share of bad luck with this barrel. I’m wondering if now you’re not running into a headspace issue? Maybe cycle a piece of virgin brass in and out of the chamber and see if your getting anything unusual. A go gauge if you have access to one would be ideal. This is still just a guess and may be no help. Must be frustrating. I hope you can get it figured out soon.
I think your head space is out of wack. Time to find a GOOD Smith.
 

woodnut

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roanoke,va.
I believe patriot007 has it right. I've never witnessed a cut in the brass head like that. It could be several things, like that brass having a lot less capacity than others creating high pressure, a chamber not cut somehow correctly. Could even be the bolt. You definitely need a competent Smith !
 
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