I bought some 'guaranteed' once fired LC10 50 bmg brass and decided to section one. While it may have been once fired the one I sectioned has definite stretch marks. I couldn't feel this with a bent piece of wire but I think you might can see the stretch mark, it looks like teeny tiny waves. You can feel it with your finger. I have several boxes of PMC brass that I know is once fired because I fired it, it reloads very well so I think I'll stick with that as I won't be doing any competitions or super long range stuff, basically it's just a big heavy plinker.

 

I'm sure this is what a lot of our LC 'once fired' brass looks like after firing in a Ma Deuce.

Steve.........

Interesting-thanks for posting the pics.

I have a bunch of LC brass as well,and don't see/feel any stretch to them.  Might have to section some of mine.

Hey Carguy..good to see you again I use mostly LC surplus and wired all of mine on the first reload and I didn't find any either.  I loaded over 900 and didn't find any with the wire test.  Can I be that lucky or am I doing it wrong?  IIRC, all LC 06, 10, 13.  I have LC 12 but they are a bitch to full length size so I keep for emergency use only.