25WSM
Well-Known Member
Be just bad luck to get a chamber and a die that were both crooked.
Shep
Shep
28 Nosler runout issues
- Thread starter Toydy
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kfreeze
Well-Known Member
I don't know what to tell you on that. That recipe doesn't go with the issues I have seen. Maybe the expander mandrel isn't square in the die is the only other thing that jumps into my mind. All of my once fired 28 stuff I did last night came out less than .002" runout. With 80% being .001" or less. All I used was a rcbs rockchucker and redding master hunter die set set to bump the shoulder back .002"
cockednlocked
Active Member
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Not to sound like a smart @$$ but are you reading the gauge right ? I have the same set up and I think the gauge is in 5 ten thousand's increments but I'm not at home to double check
25WSM
Well-Known Member
Chamber walls are normally the straight part. It's the necks that go crooked in Chambers.
Shep
Shep
bigedp51
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Tech Line & Tips (FAQs)
https://www.redding-reloading.com/tech-line-a-tips-faqs/146-concentricity-problems
Concentricity Problems
a.k.a Neck Runout With Bottleneck Cases
We have conducted many tests over the years on the various factors contributing to concentricity problems with bottleneck cases. We have repeatedly found a definite correlation between the uniformity of the brass (or lack of it) and the resulting concentricity of the neck to the body of the case.
An interesting experiment also revealed that neck turning of brass that was intentionally sorted as non-uniform, showed little or no concentricity improvement when used in standard S.A.A.M.I. spec chambers. Conversely brass that was sorted and selected for uniformity remained uniform and concentric with or without a neck turning operation.
Another interesting observation can be found in the examination of fired cases that have crooked necks "as fired" right out of the chamber. Usually the chamber is being blamed for the problem.
https://www.redding-reloading.com/tech-line-a-tips-faqs/146-concentricity-problems
Concentricity Problems
a.k.a Neck Runout With Bottleneck Cases
We have conducted many tests over the years on the various factors contributing to concentricity problems with bottleneck cases. We have repeatedly found a definite correlation between the uniformity of the brass (or lack of it) and the resulting concentricity of the neck to the body of the case.
An interesting experiment also revealed that neck turning of brass that was intentionally sorted as non-uniform, showed little or no concentricity improvement when used in standard S.A.A.M.I. spec chambers. Conversely brass that was sorted and selected for uniformity remained uniform and concentric with or without a neck turning operation.
Another interesting observation can be found in the examination of fired cases that have crooked necks "as fired" right out of the chamber. Usually the chamber is being blamed for the problem.
fiftybmg
Well-Known Member
How is the body at a different angle to the neck ?
How do necks go crooked ?
All I can tell you is, I've only seen it once. I loaded for a well known semi- custom rifle and I struggled and could never get it to shoot better than 1.25 m.o.a. I started checking the brass would come out half thou runout out of the FL sizing die and after it was fired .0025 runout, necks were turned so it wasnt the neck thickness.
Was it a oblonged chamber, reamer problem I dont know for sure. When I scoped the chamber you could see also were the throat was not cut concentric to the bore the lands were cut at an angle to the bore and the reveal was not the same on both sides of the grooves.
Was it a oblonged chamber, reamer problem I dont know for sure. When I scoped the chamber you could see also were the throat was not cut concentric to the bore the lands were cut at an angle to the bore and the reveal was not the same on both sides of the grooves.
bigedp51
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- Dec 10, 2010
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You need to test case body and neck runout on fired and resized cases. Meaning check the case body and see if it is egg shaped. If the case body is thinner on one side it will expand more when fired and bulge on that side. Then when resized the case can become banana shaped. Then when you check neck runout or bullet runout you are rotating the case on a egg shaped case body.
This problem becomes worse the more the case body expands when fired increasing how much the case body becomes egg shaped. Many people blame this on the chamber when case wall thickness uniformity is causing the problem. Meaning if the case diameter is on the minimum side of tolerances and the chamber is on the plus side of diameter tolerances the more the case can bulge and warp.
This is what the Redding FAQ was telling you, you can't make a case that does not have uniform case wall thickness shoot better. Below is an example with the case neck on the right. You can turn this case neck "BUT" neck turning does not fix the case body that warps when fired.
Bottom line, are your cases causing the problem or is the chamber causing the warped cases.
NECO CONCENTRICITY, WALL THICKNESS AND RUNOUT GAUGE
Also referred to as "The Case Gauge," this item is designed to measure:
1) The curved "banana" shape of the cartridge case;
2) The relative wall thickness variation of a cartridge case;
3) The cartridge case head out-of-squareness;
4) Individual Bullets – out-of-round "egg shape" and/or
curved "banana" shape (excepting very small bullets);
5) The seated bullet and cartridge runout of loaded rounds. The accuracy of any firearm is determined — and limited — by the quality of the ammunition shot in it. The effect of imperfections in ammunition is cumulative; each flaw adds to the influence of all others. Precision shooters spend much time and effort "uniforming" cartridge cases, using advanced techniques to eliminate variation. Yet until recently, one of the most important of these variations has not been susceptible to detection by any device readily available to marksmen.
This problem becomes worse the more the case body expands when fired increasing how much the case body becomes egg shaped. Many people blame this on the chamber when case wall thickness uniformity is causing the problem. Meaning if the case diameter is on the minimum side of tolerances and the chamber is on the plus side of diameter tolerances the more the case can bulge and warp.
This is what the Redding FAQ was telling you, you can't make a case that does not have uniform case wall thickness shoot better. Below is an example with the case neck on the right. You can turn this case neck "BUT" neck turning does not fix the case body that warps when fired.
Bottom line, are your cases causing the problem or is the chamber causing the warped cases.
NECO CONCENTRICITY, WALL THICKNESS AND RUNOUT GAUGE
Also referred to as "The Case Gauge," this item is designed to measure:
1) The curved "banana" shape of the cartridge case;
2) The relative wall thickness variation of a cartridge case;
3) The cartridge case head out-of-squareness;
4) Individual Bullets – out-of-round "egg shape" and/or
curved "banana" shape (excepting very small bullets);
5) The seated bullet and cartridge runout of loaded rounds. The accuracy of any firearm is determined — and limited — by the quality of the ammunition shot in it. The effect of imperfections in ammunition is cumulative; each flaw adds to the influence of all others. Precision shooters spend much time and effort "uniforming" cartridge cases, using advanced techniques to eliminate variation. Yet until recently, one of the most important of these variations has not been susceptible to detection by any device readily available to marksmen.
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I don't think the case is the issue, case body has little to no runout. I am using a mec marksman press (floating shell holder) and a Sinclair die with the mandrel in it (which also floats) maybe it is somehow off centre? On the bright side, I've got plenty of time to sort it as hunting is band over here at the moment (Victoria, Australia)
