I know this is a pistol round picture
Terribly worded, then. Because in the image right above that it states the cylinder is a nickel alloy.
Gets even more confusing when you look at the product page for the one rifle case they offer direct (.300 BLK) where they again state it’s a nickel alloy cylinder. 250 .300 BLK Cases | Shell Shock Technologies
The 5.56 is SS…
Having bought them and now used a few, they are stainless and they are magnetic, so they’re not austenitic like I thought they might be. They shoot very well and likely a reloader’s dream if they can get the dies.