Khornet,
M2 ball pills are steel jacket with a copper wash.
All the Lake City '06 M2 I've shot, along with the Talon '06 (which is re-milled Lake City) have had steel jacket with copper wash.
My current stock of LC 69 M2 Ball is all steel jacket.
If you have LC 66 M2 Ball that is NOT steel jacket, it is the very FIRST LC M2 Ball I've heard of that was not steel jacket.
Better check again. Make sure that magnet really works....
Swampy