Case Neck Runout!

[Phil3]

I am new to reloading, but after some experimenting, it is crystal clear that using my 223 Remington Redding FL die, with floating carbide expander ball, does add runout to the case neck. About .004" on average. Without the expander ball, it is about .001".

How can I best size the cases for use in an AR15, while minimizing runout? Seems like the Redding Full Bushing die is what I need, as it full length resizes the case, while also permitting sizing of the neck without an expander button. I am not sure why these die even have an expander. ???

Could I not use my full length die (without expander) and then expand the neck using a mandrel to achieve the same result (reduced runout)?

Thanks.

- Phil

 

[bozo699]

Phil,
If you used the redding bushing die you wouldn't need a expander, except for the fact that your shooting a ar 15. It is probably is dinging up the mouth of the case when ejecting, if that is the case you will need either a expander ball or a expander mandrel die.
Wayne.

 

[Phil3]

I still do not understand why any bushing die has an expander button. If the bushing is sizing the neck, why would you then drag an expander back through the neck, probably ruining the neck sizing the bushing just did? I must be missing something here.

- Phil

 

[bigedp51]

Phil

If you have a dinged case neck the ball expander is used to straighten the neck.

 

[BoydAllen]

For unturned necks, in a bushing FL die, the expander can be beneficial. When you run an unturned neck into a bushing, the neck thickness runout ends up distorting the average diameter and roundness of the inside of the neck. If you choose a bushing that only leaves the expander ball with a little work to do, so that its passage through the neck is barely discernable, there will be no damage to the alignment of the inside of the neck with the CL of the body of the case. The reason that one piece dies, with their expander balls cause crooked cases, is that the neck portions of the dies are too small and leave a lot of work for the expander to do, which pulls so hard on the neck that the shoulder yields slightly, asymmetrically, cocking the neck. If the pull on the neck is low, this does not happen. Obviously, if changes in neck tension are needed, custom expander diameters may be required. Even with turned necks, an expander can help correct neck dents.

 

[fdshuster]

Phil: If someone is using brass with a lot of varience around the circumference of the case neck, (neck wall thickness), they are given the option of using the expander button to transfer those differences to the outside of the case, and with the generous chamber neck diameters of a lot of factory chambers it would probably have very little effect on accuracy. On the other hand, those of use using Lapua 223 brass are using the neck bushing without the expander, since the neck walls are very consistant in thickness. The die maker is giving you the choice. I tried using a neck bushing die for my AR-15's and had to call several alibis in the middle of a match because the bolt would not fully go into battery. Returned to my "standard" one piece sizing die (also redding) with the expander & have never had a problem again. The bushing will leave the base of the neck (at the shoulder junction) with a small expanded area since the bushing cannot size all the way down to the shoulder, and that's the area that may prevent the bolt from fully closing. You may try measuring your neck wall thicknesses, with a tubing mic, for example & segregating those that have more than .001" differences.. That's my limits for judging the quality of the brass. I now use neck bushing dies for my bolt guns only, not the AR's.

 

[bozo699]

Very well put Frank, I don't shoot my ARs much and I didn't think about the bushing not going all the way to the neck shoulder junction. Your right though it wouldn't,and unless you had a very sloppy chamber you would have chambering problems. I don't shoot mine in any kind of competition, I buy most of my ammo from black hills, but the little I have loaded for them I just use a cheap rcbs f/l die and have had no problems chambering them. I am sure I have run out.
Wayne.

 

[Phil3]

I just full length sized 50 new Winchester case, with a Redding FL die, floating carbide button in place. Results are not good. For Winchester brass, the cases did not look too bad (or great) averaging around .0015" neck wall thickness variation and .0035" neck runout, right out of the bag. After the resizing, virtually all cases had runout of at least .004", with some at a whopping.008". Is this just endemic to full length sizing dies, or is there something amiss with my procedure? Or, are bushing dies the only way to improve runout? Since it was stated above that bushing dies may not work in ARs, I wonder what AR users are doing to minimize runout.

Thanks.

- Phil

 

[bozo699]

Phil3,
Re-read BoydAllens post, That explains your problem pretty clear to me. As you stated your win brass is anything but perfect, IMO you need to turn the necks about 70% to 80% clean,Lube the cases up good including inside the neck, polish your expander ball real good, then leave it loose or put a O-ring under adjusting nut. The other option would have a custom honed die made, then if your mouths are not dinged up after extraction you could use the custom f/l die w/or without expander ball as you wished.
Wayne.

 

[jonbearman]

You need a neck lubricant like mica/graphite or moly etc.That may cure your ills.

 

[RonAKA]

I still do not understand why any bushing die has an expander button. If the bushing is sizing the neck, why would you then drag an expander back through the neck, probably ruining the neck sizing the bushing just did? I must be missing something here.

- Phil

I use an expander in my Forster bushing die. It probably only opens the neck by 1/3 of a mil at most. My thoughts are that the fit to the bullet (ID) is more important than the fit to the chamber neck (OD). So if you only size the OD then you transfer any irregularities to the ID.

Forster allows you to do a couple of things different than Redding. First they position the expander ball up near the neck to minimize the concentricity disturbance it may cause. Second they sell expander balls in 1 mil increments so you can select how much you want to open the ID.

 

[bozo699]

Ron,
I want to try one of the forster ultra seater dies and the neck die you can bump the shoulders with where have you been getting yours?
Wayne.

 

[BoydAllen]

In rereading your question, I see that you are sizing for an AR. On another board, I recently read a post from an experienced match shooter that told of malfunctions caused by a bushing die's inability to reach the part of the neck just in front of the shoulder. Based on this new (to me) information, my suggestion is to have the neck of a one piece FL die honed out so that the expander ball has less work to do. I understand that Forster will do this to their dies for only $11.

 

[wapiti25]

Polish the button, a carbide button is better. Then lube the inside of the case with one of the lubes such as Imperial Application Media with dry neck lube or Hornady One shot as these will not have to be cleaned out and will not harm the powder or primer. Both of these have been suggested by others but I just changed the words. These are cheap to try and they have helped me. Let us know if this helps.

 

[bigedp51]

Below at the bottom of the page is a link to this good article on reloading for the AR


Reloading for .223

Dies:

Redding Type S Full Length Seating die with Neck sizing bushing 0.245" (76 style)

This is a full length sizing die with decapping rod and carbide sizing button for internal neck sizing. It also includes a neck sizing bushing for external neck sizing.

To determine bushing size, measure the outside neck diameter of your loaded cartridge with a precision micrometer. From this measurement subtract 0.002"-0.003". This allows for a 0.001" brass "spring-back" after sizing and will result in a proper bullet press fit of 0.001"-0.002".

Redding Competition Seating Rifle Die for .223

This die will allow you to set your seating depth to 0.001" accuracy and repeatability.

http://kingfisher.0catch.com/guns/reload.223.html

 

[jonbearman]

I have a redding full length sizer I have been using for years and dont get more than .002 thou runout which is acceptible in a rifle.My rifles are the ar15 and a rem bolt gun.It still(both) shoots great groups and is consistent.I use neck lube as this cured my ills.

 

[BoydAllen]

On the subject of neck lube, if you brush necks (not down to clean brass please) and dip them in Imperial Application Media, before finger applying lube to the outside of the case, your use of any die with an expander ball will be vastly improved, and there will be no need to clean the inside of the case necks after sizing.

On the other hand, years ago, when I tried motor mica for the same thing, I was not at all impressed. Save yourself the trouble.

 

[Phil3]

All my experiences reported have been using Imperial Application media for the interior of the neck and Imperial was lubricant for the exterior. Am also using a carbide expander ball. Overkill for the interior of the neck, but won't hurt.

After playing around with the new brass, I did a few things and learned a bit more.

Fired cases seem to be much more cooperative when it comes to minimal runout than the new Winchester cases. I figured the FL die would straighten out anything, fired or not, but maybe not. ??? Secondly, I cleaned the die, and that seemed to help. Thirdly, the decapping rod seems to be slightly bent, potentially pushing the floating carbide expander ball off center. I tried resizing with the rod screwed in, but not locked down and that seemed to help slightly. Lastly, simply slowing down when extracting the expander from the brass also seems to help.

I am not that impressed with the Winchester brass, but given an AR beats it up, not so sure I want to invest in Lapua brass. Any thing else that costs less than Lapua but better than Winchester?

- Phil

 

[bozo699]

Phil,
I have had good luck in some calibers with nosler. some cal were on par with norma and some were worse than rem. but as cheap as they are it might be worth a try.
Wayne.

 

[holstil]

Where can I buy Imperial Application media?