Winchester Brass Neck Thickness Differences

[minnesotamulisha]

Morning everyone. Last night I was neck sizing some Winchester 308 brass, or maybe trying to is a better way of putting it.

The first few pieces went just fine. Then, the pressure needed to move the handle through a full stroke of the press increased dramatically.

What I found is that the sizing ball runs through the neck, but the bushing in the Redding S Type sizing die, is too large and is not leaving any marks on the brass. The bushing is a .336".

All of the brass has only been fired once, in my rifle. It was factory ammo from Winchester. Not sure if it was the same lot, but I did buy three boxes all at the same time, so I would hope it would be.

Out of the 28 pieces of brass, there are 15 that neck sized normally, and 13 that only ran the ball through the neck.

Would this mean that the neck thickness is our of spec on these pieces of brass?

Has anyone else seen anything like this?

Thanks for the help.

Adam

 

[amlevin]

It sounds like you aren't turning the necks if only to make sure that the neck thickness is even around it's circumference and from case to case.


If you neck size only cases that are uneven in the neck thickness then you run the risk of inducing runout at the bullet. Thickness variations are all "pushed to the inside and now show as variations in ID.

I've found some Winchester cases to have as much as .002" variations in neck thickness. This would give you that same amount of bullet runout if you neck size it without evening up the thickness first.

You don't have to turn the necks down any more than necessary. At least enough so the cutter shaves off metal for 180-270 degrees of rotation.

FWIW, even high-end brass like Lapua has some variations in neck thickness, just not as much. Regardless, it all contributes to runout in a finished cartridge.

 

[watercam]

To answer your question, yes I have seen large variance with most U.S. factory brass. There is a bigger issue though. You might consider not using the expander ball with type S dies. The idea is to choose the bushing that gives you the tension on the bullet that is minimal in regards to how the cartridge is being used/abused. Feeding from a magazine usually dictates about .003" less than the diameter of a loaded round. Hunting rounds perhaps .004-.005". The idea is to have uniform tension for better accuracy. Single loaded match rounds go about .001" with no issues at all.
Referring to the post above, if you outside turn your necks to some sort of uniformity the bushing can then do it's job and the expander ball (which does nothing for your concentricity) can be eliminated. This also helps keep brass from 'growing' thus reducing the trimming you will have to do periodically.

 

[dalej]

Case neck run out may be an indicator of brass being thin on one side. If you don't have tools to measure cartridge wall thickness roll a fired case over a pane of glass to identify any eccentricity that may exist. If the neck run out extends to cartridge body cull the case. Outside neck turning will not help. Firing a cartridge thin on one side will result in bullet entering rifling crooked as thin side of case expands first.

 

[minnesotamulisha]

I don't think that the neck thickness is inconsistent. The neck is thinner from one piece of brass to the next.

On the pieces of brass that don't show signs of neck sizing, the OD is .326-.327". On the pieces that do show signs of neck sizing, the neck OD is .3365, same as the bushing in the neck sizing die.

 

[minnesotamulisha]

Oh, and MTM, I attempted to removed the expander ball last night, but I couldn't get it loose from the stem. I am not sure I want to put pliers to it as it might scar it up and wreck the inside of my necks if I do need to use it at some point.

 

[XTR]

You may need to consider a size smaller bushing with WW brass. I shoot a lot of it. and I don't turn necks. My loaded necks shooting WW are ~.332, necks on loaded Lapua Palma are ~.336.


I'm a big fan of Lee Collet sizers for most applications.

 

[Brians356]

Oh, and MTM, I attempted to removed the expander ball last night, but I couldn't get it loose from the stem. I am not sure I want to put pliers to it as it might scar it up and wreck the inside of my necks if I do need to use it at some point.

I don't have the die to hand (I am at my office) but I believe you'd be better off removing the whole stem (assuming you don't need to also de-prime the brass in the same step). The stem can be gripped with pliers with impunity, it has a knurled area for this purpose as I recall.

It's hard to imagine your WW brass has that much variance in neck wall thickness - on the order of 5 thousandths?! Something doesn't compute in my feeble brain. Are you sure some of them haven't been neck turned by someone? Where did you get the brass, and are all from the same lot?

 

[skiutah02]

You may need to consider a size smaller bushing with WW brass. I shoot a lot of it. and I don't turn necks. My loaded necks shooting WW are ~.332, necks on loaded Lapua Palma are ~.336.

^this

Been shooting Winchester brass in 308 for the past two years (multiple batches) and my unturned-neck loaded round is 0.333ish and I have used the 0.331 bushing for typical tension. 0.337-8 loaded round on unturned Lapua brass with 0.336 bushing.

 

[Brians356]

Ok, I realize now you have been measuring neck ODs of unloaded cases. Probably you are using too large a bushing, and some case were previously fired in different chambers.

It's something of a Catch-22 but you need to measure the neck ODs of a few cases with bullet already loaded, then subtract 2-3 thou from that to determine the bushing size. Do you have a conventional full-length 308 Rem die you can use to load a few dummy rounds for measurement? Or, as "skiutah02" suggested, try a .331" bushing in your neck die.

 

[bigedp51]

minnesotamulisha

Below is a factory loaded once fired Remington .223 case with approximately .004 neck thickness variation. To me a bushing die is a specialized die and the cases should be neck turned to get the best out of this type die. Even if you had a standard full length die with a expander button you would need uniformed necks when striving for uniform neck tension and minimum runout.

I use the above neck thickness gauge for sorting cases and deciding if any prep work is to be done to these cases. The case above will not receive any prep work and will be fired in my AR15 carbine, the better cases will be fired in my AR15 A2 HBAR and the best cases used in my .223 bolt action.

Bottom line, without a neck thickness and runout gauge I would bet you are creating more neck runout than the case had when new. And mixed brass is not helping with "uniformity" and "accuracy", so get some gauges and sort your brass.

 

[bigedp51]

minnesotamulisha

Also if the cases have larger variations in neck thickness there is a very good chance the case body will also vary in thickness. When these type cases are fired they will warp and become banana shaped and drive you nuts with larger groups. This is why the poorly made cases are full length resized and just used as blasting ammo in my AR15 carbine. You can prep these type cases till the cows come home and you will still have junk warped brass with the bullets misaligned with the axis of the bore.

Below checking case wall thickness and for thinning in the base web area on a .243 case on my RCBS case mastering gauge.

Below is a image from the internet showing how the gauge is setup and works. (the cases do not levitate off the end of my finger)

Below is from the NECO gauge webpage, and I didn't invent the term "banana shaped case".

Below is the RCBS case mastering gauge measuring neck runout, in the left rear of the photo is a Hornady concentricity gauge used to "bend" the warped banana shaped cases into submission. : (knock on wood)

 

[CatShooter]

Oh, Edward, how often do I have to tell you.

Brass is like wine.

If you let wine lay for long periods, the stuff in it (sediments and such) will settle to one side. That is why you need to turn wine 90 degrees every so often.

It is the same with your 223 brass. If you let it set on it's side for long periods of time, the necks will get thicker on one side... 4 thou in your case.

Turn your brass 90 degrees every few weeks, and all will be fine

 

[bigedp51]

Oh, Edward, how often do I have to tell you.

Brass is like wine.

If you let wine lay for long periods, the stuff in it (sediments and such) will settle to one side. That is why you need to turn wine 90 degrees every so often.

It is the same with your 223 brass. If you let it set on it's side for long periods of time, the necks will get thicker on one side... 4 thou in your case.

Turn your brass 90 degrees every few weeks, and all will be fine

CatShooter, if I didn't like you so much I would tell you to go (expletive deleted) yourself! (but I know your just trying to be as funny as I am..........and failing) :

Do you know what the favorite wine is in this forum?

"I should have bought Lapua brass instead". waaa, sob, hic! :'(

 

[Brians356]

Hey "bigedp51", got any pictures you can show us?

 

[bigedp51]

Hey "bigedp51", got any pictures you can show us?

Yes I do, below is a building my wife and I are standing in front of that the Italians forgot to rotate every few weeks, even after Leonardo CatShooter told them to.

And another in Aruba "reloading" a few weeks ago.

 

[Brians356]

Hey "bigedp51", got any pictures you can show us?

Yes I do, below is a building my wife and I are standing in front of that the Italians forgot to rotate every few weeks, even after Leonardo CatShooter told them to.

Whoever was taking the picture needed to level the camera. How much did you tip him?

 

[bigedp51]

Hey "bigedp51", got any pictures you can show us?

Yes I do, below is a building my wife and I are standing in front of that the Italians forgot to rotate every few weeks, even after Leonardo CatShooter told them to.

Whoever was taking the picture needed to level the camera. How much did you tip him?

brians356, please read the forum rules, triple thread hijackings are not allowed even if your trying to raise your post count. :

 

[Brians356]

brians356, please read the forum rules, triple thread hijackings are not allowed even if your trying to raise your post count. :

Uh, what's a post count? Is that like a thread count? (My S.O. uses that term when she's shopping for bedsheets.)

 

[minnesotamulisha]

Out of the 28 pieces, the 15 that did size the neck are all about . 332" in diameter at the neck. Which makes no sense because the bushing is a 335. Of the pieces that didn't get the NE k sized, the pieces are 332-3325. All these pieces of brass were bought as new factory loaded ammo. All of it is Winchester Super X Power Point. It was fired one time from my rifle. That is all. I don't have the lot info for the ammo as I tossed the boxes.

I understand that neck thickness is what is the issue here, but wouldn't the neck expand when the round was fired and open it up to match the neck portion of the chamber in my rifle? Especially if the neck was thinner I would expect it to expand even more than a thicker walled case.