I have some 308 brass that drops down in a case gage below recommended size. Is this now scrap or can it be used in first an AR-10 and secondly in a bolt action?
If shoulder is bumped back too far it is not ideal.
depending on amount, you could seat bullets to lands. This would hold it in place. Use mid level load and blow it back out. Case head separation will occur sooner due to overworking so check each subsequent cycle prior to loading.
How much is shoulder set back?
It looks like .004 max below the minimum on the gage. I was hoping I could resize it by firing it. Case length grew considerably with this so in for trimming too.
It will be fine if you hold headspace with long seated bullet. Touch the lands.
The case stretching occurs near the base, not the neck. Case life will be shortened so keep checking every cycle.
Size with a small base die without touching the shoulder. That might help.
Expand the neck with a 8mm mandrel than size the outside of the neck with a 308 die just enough to chamber. Not sure that will work well with your autoloader.