The following speaks to Fritz's statement about steel v copper FMJ ammo identification
What is steel-jacketed ammo?
https://www.thehighroad.org/index.php?threads/what-is-steel-jacketed-ammo.31351/[EXCERPT]
Steel-jacketed ammo is ammunition in which the bullet (not the case) has a steel covering; some manufacturers (usually military) use steel because it's cheaper than gilding metal (the copper alloy used on most jacketed ammo). If you've got a magnet and/or a hacksaw, it's usually fairly simple to tell if your ammo has a steel jacket.
Looks alone can fool you, because they do make copper-washed steel-jacketed ammo, which just has a thin coppper coating on the steel jacket. If a magnet sticks to the point of the bullet, the bullet will either have a steel jacket or a steel core (or possibly both), and if you cut through the bullet with a hacksaw, you'll be able to see if there's anything besides lead in the core. HTH.
SDC, Jul 15, 2003 #2