Were you still getting failures to chamber even after the plunk test?
I don't know much about reloading 380, never done it, but loaded for most other stuff at one time or another.
With 3 grains I wouldn't think the case space being too little would be an issue.
When I do the plunk test, I take my finger and try to press the cartridge into the chamber hard as I can. Then invert the barrel and see if it falls out freely. This tells me if the bullet is touching the lands.
I'd have to break out the book to see where 3 grains of 231 sits on the menu. That of course won't effect chambering but if it's close to max the case space might be slightly more critical, but I still doubt it.
In Memory of Paul "Dietrich" Stines.
Dad: Say something nice to your cousin Shirley
Dietrich: For a fat girl you sure don't sweat much.
Cue sound of Head slap.
RIP Muggsy & TMan
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