As an Army Air Force pilot during World War II, one could expect to take fire from time to time — but the bullets weren't always coming from Axis aircraft. Sometimes, it was your fellow servicemen and women taking the shots.

The Bell P-63 Kingcobra fighter, developed in 1942, never got much love from the American military, which had a preference for the legendary P-51 Mustang. Instead, over 2,400 Kingcobras ended up in Soviet control under Lend-Lease, a wartime program to provide American allies with gear to fight Germany and Japan. That doesn't mean the US didn't put the P-63 into service, though: it ordered a bunch as the RP-63 "Pinball," a substantially modified P-63 designed specifically to be fired upon for target practice. Though primitive drones did exist at that time, airmen and women needed to hone their skills firing at the full-scale Messerschmitts they'd be encountering over Europe, which is where the Pinball came in. And real, actual pilots were at the controls as they were taking fire.

The RP-63 had a couple unique features that kept its operators relatively safe. Roughly a ton of armor was added, the canopy was reinforced, and the would-be aces in hot pursuit were firing "frangible" bullets, a mixture of lead and plastic that would disintegrate on impact with the Pinball's thick plating. Special sensors located throughout the fuselage detected hits, triggering a light in the nose cone so pilots could tell when they scored. Inside the RP-63's cockpit, a counter kept track of the tally.

Just like modern target practice drones, the Pinballs were painted orange. The big difference, of course, is that we don't send pilots up with them anymore — the decommissioned F-4s and F-16s in the Air Force's target practice inventory are often shot at with missiles, which are a little harder to protect against than the .30-caliber cannons Pinball pilots dealt with in the 1940s.