Interesting. It took me a while to figure out that there is metal to metal contact. It sounded like the armature slides on the rail. Couldn’t figure out the configuration, but in looking at the bottom graphic, it looked like the legs of the armature point aft (laying flat on the lower rail) with the business end pointing forward (is it pushing a projectile in front of it, or is the armature part of a projectile?
In any case, yeah. My knowledge about this was outdated. Last I heard, it was a maglev process where nothing touched on the way out, and wear of components was not only not an issue, but the non-wear in that setup would have been an advantage. (I probably read that in the piece of crap magazine “Mechanix Illustrated” not realizing the magazine was in the process of jumping the shark...)
I guess they didn’t go that direction, probably because the energy required to maglev the projectile all the way out was too extensive.
Sigh. No wonder erosion would be an issue.