Question about case head separation in 223 AR15

[Robert4]

I have some 223 brass I have used for powder puff loads in bolt rifles. These cases are .003 to .005" shorter in headspace than a go gauge so will have around .006 to .008 headspace in my AR15. While it's unlikely I would have a case separation firing these, it could happen. They all pass visual and the paper clip test. Have not loaded any yet.

So I'm wondering how serious is a case head separation in an AR? I can't seem to find much about this. Most searches devolve into blown cases from over pressure experiences. If I do load these, it will be throw away brass with modest powder charges for plinking.

 

[Hoser]

Using a tapered expander, neck them up to 6mm.

Then load them normally with your FL resize die set to 2 thou shoulder bump for normal brass.

 

[spife7980]

Just shoot them. Id say most times factory ammo will have that at least

Case head separation is "serious" but all of mine from taking brass one firing too far havent scored the chamber or anything negative so I guess Ive been lucky.
The biggest hassle will be getting the front half of the case body out of the chamber, especially if the gun cycles and the following round crams it in there. In that case a shotgun brush on your cleaning rod pushed in just past the neck and then retracted so the bush bristles act like barbs and pull the brass out is the easiest method Ive come across and has been sufficient thus far. Ive heard of some guys with it really jammed in have used a properly sized drill bit to get some bite on the brass and spin it loose from the chamber but thats a last course of action to me.