I would have been ecstatic if any one of these had shown up, but three different types of WWII German experimental 105mm artillery projectiles in one buy? Seller got them in sale of stuff from a museum like 45 years ago. These were captured at the Hillersleben Proving Ground in Germany in 1945. They are early "sabot" projectiles which use a "subcaliber" projectile in a cannon with a larger bore in order to get the projectile moving faster than it could go in the traditional way. Today all Army tanks have sabot ammunition to defeat the armor of other tanks. The green projectiles are high-explosive types, and the black one is a solid armor-piercing one. Sabots are usually designed to "discard" after the projectile leaves the cannon.
On the bombing and target range at NAS Fallon, NV we, obviously, didn't have any tank operations. I have observed 33lb inert 'bombs', delivered by aircraft, penetrate armored APCs and leave a clean hole with 4 distinct lines from the fins. That alone would've likely killed everyone in it.
If hole was in the top of the APC, yes maybe practice bomb. If in the side, was more likely a tank round, but there'd be a matching exit hole on other side. National Guard may have done some tank firing there on weekends.
No. No tanks there.... This is NAS, Naval Air Station, though we, of course, had Marines in and also Air Force. I was running the target spotting team when the APC was hit. We saw it when we went out to light the smudge pots for night flights. These were 33lb, no explosive round, Mark 33s.
