Thread: 223 over resized brass?

Originally Posted by Tentman

My pick on this is that if loaded in their current state they won't even go bang, but if they do, then a case head separation is a dead certainty!

And how did they get like this?

Greetings @Tentman,
I'm not familiar with the nut thingy but I went out to the shed and a.223 case in my .330 chamber looks about the same. Yes your cases have been grossly oversized by around 0.020" or 0.5mm. Mixing up the competition shell holders is not to blame as this will make the cases longer rather than shorter. I would check your fired and unsized cases with the primer out to be sure. You also may want to measure one of your sized cases before you load it just to be sure. How this happened is a worry. It may be a dud (or ground) die or shell holder. Firing very light loads can set the shoulder back as can firing them in some semi auto rifles but 0.5mm is a lot. Firing protrusion is generally around 1.5mm or so and the rounds would probably fire but whether they would separate on the next firing is anybody's guess. I would just recycle them and buy some new cases. It is just not worth bothering with anything that is substandard.
Regards Grandpamac.
PS. The possibility of small base dies occurs to me. These size the body more than standard dies but don't know if they set the shoulder back. My guess would be substandard or butchered dies, shell holder or both.