My beautiful reconditioned 5.56mm cases are giving me a headache

[gmerkt]

In another thread lately, I mentioned that I had a batch of 5.56mm reconditioned cases that I bought some years ago. They were advertised at "prepped." They are beautiful, obviously liquid tumbled with pins. When I first got them, I ran about a dozen through a cartridge headspace gauge and they were either uniquely uniform as a batch or had been trimmed. The primer pockets were swaged. Aside from giving the case mouths a slight chamfer, I assumed they were ready to go. I have been storing these in a big, round, metal tin. I'd thought there were 1,000 in there; my markings on the outside say 500. However, after removing 100 tonight, I may be wrong about the 500. There actually may be 1,000 there. Also, I'd remembered them as Federal, they are LC's with three different dates.

After mentioning these the other day, I decided to get into them. Who or what was I saving them for? I have some Hornady 75 gr. Interlock HD bullets that I want to try out. I gave the cases a bit of a chamfer at the mouth, then I primed them with CCI 450's. I got my seating die calibrated to the work and set up to charge with BL-C(2) powder. Then I got into seating the bullets. Right away I could tell something wasn't quite right. The bullets seated hard, yet had insufficient tension. I struggled along and loaded about 30 pieces then I stopped and thought, "This just isn't right." Close examination of the cartridge showed that the case mouth had a slight, offset bulge where the bullet was seated. I miked a few of the bullets, they were right on at .224. I rolled one of the loaded rounds along the bench, and I could see the bullet was slightly askew, out of concentricity, whatever you'd call it. Next I got a few cases that I'd prepped myself at some earlier time, and loaded some of the 75 gr. bullets into them. Those loaded just right, with appropriate resistance when seated, yet having good bullet tension. They rolled across the bench without any degraded concentricity. So my shiny, store-bought cases had to be the culprit.

They were. What I found was that the case mouths hadn't been sized correctly. My guess is, whoever "prepped" these did not use a sizing button. That's the little ball on the end of the decapping pin that does the final sizing of the case mouth. The die body does the initial size-down, then the button gives it the final size on the up-stroke. The case mouths were too small. When a bullet was attempted to be seated, it deformed the case mouth. This deformity not only caused the bullet to be slightly skewed, but warped the brass mouth in a way that disallowed uniform tension on the bullet, and that's how I wound up with loose bullets in a tight case mouth. This seemingly contradictory situation sounds illogical but that's what happened.

This wouldn't happen with a 7.62mm NATO or .30-06 case. Because the brass material is thicker than the 5.56mm. I've loaded .309 bullets into .30-06 before without any of this.

During the course of figuring this out, I used two different bullet seating dies. One, an RCBS standard seating die. When I started having issues, I changed to a Hornady "precision" seating die, the kind with the long sleeve that comes down and supposedly guides the bullet into the case mouth better. No change.

I can't remember now where I bought these. Being Lake City, they are dated and the newest one is 2016. Using the sizing button (only) on my own sizing die, I opened up the mouths of the 100 I was working on. BUT: I have all the rest of those remaining in the tin to do as well.

They were supposed to be "once fired." I found several with the four little stake marks around the primer pocket that some ammo remanufacturers use. Tumbling with pins is an equalizer.

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[Certaindeaf]

Never judge a piece of brass by its shine.

 

[Carguy]

Everything could be as advertised, but the case mouth expander, "sizing button", was probably worn. I recently discovered that after decades of use, my 308 expander had worn down by .003". I was starting to have trouble with my trimmer, as the pilot wasn't going into the case mouth and started measuring everything. A new decapping assembly and everything was fine again.

 

[osprey]

A perfect application for a lee neck collet die!

 

[fstdraw]

I size everything, new or otherwise, to avoid just this problem. OP do resize, it will be done in an evening and all will be right. GL.

 

[ar addict]

My guess is the brass was trimmed after being resized.
A dillon trimmer die will compress the neck to keep brass
from spinning.

 

[HotLoad]

I load 223/556 on a progressive press in two passes. The first pass is all the prep steps. The second is the loading steps. I raise the size die enough to only pass the resize ball through the neck. This makes the neck size uniform again.

 

[Local Loader]

I've gotten in the habit of repreping any used brass I buy that says "already processed" as I've found over half of what I bought needs reprocessing, so I reprocess it by default.

 

[gmerkt]

A perfect application for a lee neck collet die!

Yes, I used one of these to neck size the 30 or so that were distorted. However, the rod holding the decapping pin is just a taste undersized to .224 so as to allow passage of the case mouth. But it wouldn't open up my undersized case mouths quite enough. So using the expander button on a sizing die was the solution.

 

[gmerkt]

Everything could be as advertised, but the case mouth expander, "sizing button", was probably worn. I recently discovered that after decades of use, my 308 expander had worn down by .003". I was starting to have trouble with my trimmer, as the pilot wasn't going into the case mouth and started measuring everything. A new decapping assembly and everything was fine again.

My guess is the brass was trimmed after being resized.
A dillon trimmer die will compress the neck to keep brass
from spinning.

Could be either one of these which I hadn't thought of. Of course I wouldn't know about the Dillon trimmer. When I had the Dillon set-up, I didn't have one.

The expander button, those don't wear out real fast if you use liquid lube or dry lube (mica powder) inside the necks. Of course anything will wear out.

 

[gmerkt]

I size everything, new or otherwise, to avoid just this problem. OP do resize, it will be done in an evening and all will be right. GL.

Over the years, I've gotten used to the idea that new brass isn't "prepped," per se. BUT: When it is advertised as prepped, I'd like to get what I paid for.

 

[gmerkt]

I've gotten in the habit of repreping any used brass I buy that says "already processed" as I've found over half of what I bought needs reprocessing, so I reprocess it by default.

Yes but this cancels out the reason I paid money for someone else to do it for me. I am perfectly capable of doing the work myself. But once in a while, I like to have the luxury of "buying my way out" and paying someone else to do it. I'm old and still learning.

 

[gmerkt]

I load 223/556 on a progressive press in two passes. The first pass is all the prep steps. The second is the loading steps. I raise the size die enough to only pass the resize ball through the neck. This makes the neck size uniform again.

Alas, I'm loading single stage. I usually limit my efforts to 100 pieces at a time. Staying within the confines of 100 piece batches, any disastrian episodes are limited in scope. Actually, I don't really know why I'm still loading .223 because I have so much stacked away that I don't know when I'll get to using it.

 

[American123]

Takeaway here is that shiny pretty brass does not guarantee ready to load brass.

Buyer beware when buying used things.

 

[Carguy]

The expander button, those don't wear out real fast if you use liquid lube or dry lube (mica powder) inside the necks. Of course anything will wear out.

I do lube the expander, but have used that die for almost 40 years.

 

[DizzyJ]

I use an expander mandrel to ID size. I prefer this over pulling a "button" style expander up through the neck.

 

[ageingstudent]

I use an expander mandrel to ID size. I prefer this over pulling a "button" style expander up through the neck.

With that mandrel, do you use a collet type die to press the neck against the mandrel?

 

[DizzyJ]

With that mandrel, do you use a collet type die to press the neck against the mandrel?

No. It's sized down with the sizer die and opened up to the correct size with the mandrel. I tend to use the carbide expanding mandrels as they're pretty "slick" and don't require the use of lubrication. Never had an issue with galling.

I also have titanium nitride coated steel mandrels but the carbide seems to require less maintenance and no galling.

The steel mandrels can be useful as far as being able to modify the diameter for which one can tailor neck tension. Neck tension has been shown to be a variable which will affect group size. Lubrication will however be required when using a steel mandrel.

I've used the Lee collet style dies in the past. I assume that's what you're referring to?

 

[ageingstudent]

No. It's sized down with the sizer die and opened up to the correct size with the mandrel. I tend to use the carbide expanding mandrels as they're pretty "slick" and don't require the use of lubrication. Never had an issue with galling.

I also have titanium nitride coated steel mandrels but the carbide seems to require less maintenance and no galling.

The steel mandrels can be useful as far as being able to modify the diameter for which one can tailor neck tension. Neck tension has been shown to be a variable which will affect group size. Lubrication will however be required when using a steel mandrel.

I've used the Lee collet style dies in the past. I assume that's what you're referring to?

Yes the lee collet. Interesting. I haven't done high power rifle for awhile. Always interested but don't have the time to dedicate.

 

[bpyycpyy]

I guess it shows that "prepped" likely means different things as I'm sure we all have different prep procedures for getting our brass from fired to firing ready. Like others mentioned, I always assume that I need to do all my prep steps.