Something odd happened and was wonder if anyone had any ideas. I've reloaded the brass 3 or 4 times. When I reloaded again, there were 17 cases out of 100 with expanded necks (about .228) so the .224 bullet passes through to the powder. I recovered the bullets and the powder but now don't know what to do with the primed brass. I shot the other brass and none of them have expanded necks. The bullets were the same with Hornady 55 gn SP. The ARcomp powder ranged from 19.5 to 20.3 gn. Any ideas?

Something odd happened and was wonder if anyone had any ideas. I've reloaded the brass 3 or 4 times. When I reloaded again, there were 17 cases out of 100 with expanded necks (about .228) so the .224 bullet passes through to the powder. I recovered the bullets and the powder but now don't know what to do with the primed brass. I shot the other brass and none of them have expanded necks. The bullets were the same with Hornady 55 gn SP. The ARcomp powder ranged from 19.5 to 20.3 gn. Any ideas?

Just out of curiosity did you full length size or just neck size the brass before you reloaded them? Is it possible you missed running these few pieces of brass through the sizing die before trying to reload them?

What brand and type sizing (Full Length or Neck Size) die do you use?

Are you sure you followed the manufacturers instructions when you installed the sizing die the first time? Did you check the locking ring on the sizing die to see if it came loose and your die is still set at the correct height?

The role of the sizing die, whether neck or full length, is to resize the neck back down to the proper diameter so it will hold a bullet and provide the proper tension around the bullet. It sounds to me like those pieces of brass did not go through the sizing die. Or your die is not set properly.

Since you are reloading .223 I will assume they are being shot through a semi auto rifle. When you reload for a semi auto it is imperative that every piece of brass gets full length sized each time before reloading. And I suggest very highly that you invest in a case gauge as well. The case gauge will tell you if the brass has been sized correctly including neck sizing and OAL. The importance of this is to make sure the cases don't get stuck in the chamber of your semi auto rifle.

if you're using a full length sizing/decapping die, you can remove the decapping/expanding rod before you resize these cases.  This way you don't have to worry about having to re-prime the brass.

Are you using the LEE COLLET Die?

What kind of brass? Same headstamps?

Don't know if this is related but maybe should check your brass wall thickness at the mouth if it is an uncommon brand.   A ball micrometer is useful for this (I plan to get one).  RCBS has one for under $60.  Can compare measurements to LC brass
Other than that, like all the others said, use a good brand FL die and get a Dillon or Wilson case gage. 

In addition to what Inspector has already covered, it may help to describe your reloading process and setup. Definitely sounds like either you missed running those brass through the FL die or have mis-adjusted dies.

I too will highly recommend either a quality case guage, RCBS precision mic and/or somehting similar. If you aren't measuring, you are guessing.

Lee FL die. I use a breech lock bushing. I would think that if I did something wrong with installation, that the problem would continue with the next set I prepared. Perhaps a bit of residue on the expander pin caused the overexpansion but came off. The problem with this is that the overlarge necks were not consecutive as I can recall.

I use a depriming die to remove the primer, then wet clean the brass. I then use the FL die to resize the case and then trim.

I appreciate all of the comments and suggestions. Is there anyway I can recover the primers or are they toast? After depriming, I can resize the cases and see if they're still too big.

PMC. It's no Norma but only one split case so far out of hundreds. I was wondering if metal fatigue was causing it to expand the diameter rather than split. I've never heard that before but it's a theory.

What kind of brass? Same headstamps?

Oh I get it. I'll try that now.

if you're using a full length sizing/decapping die, you can remove the decapping/expanding rod before you resize these cases.  This way you don't have to worry about having to re-prime the brass.

Oh I get it. I'll try that now.

alternatively, you could loosen the collet on your Lee FL Sizer/decapping die and set the rod higher up in the collet.  if you set it high enough, the decapping pin will not come in contact with the fresh primer thereby saving you from wasting a perfectly good primer.

if you plan to stick with your procedure of using a separate universal decapping die, you could always file down the decapping pin in your FL sizing die.  This will allow you to get the expander action as well as the neck sizing action, from your FL sizing die, but without the decapping feature.

Okay, so I took the expander pin out and resized. The necks are all the proper diameter now. It looked like I had resized them originally. The pin was slightly rusted, probably from the wet cleaning and not drying completely. I used CLP on the pin and will reinsert it into the FL die. Thanks all. Still not exactly sure what caused it in the first place but will know what to look for if it happens again.

if you're using a full length sizing/decapping die, you can remove the decapping/expanding rod before you resize these cases.  This way you don't have to worry about having to re-prime the brass.

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