Ryan:

.223/5.56 Tracer and/or Incendiary Tracer could both ignite it quite sufficiently, but as others have pointed out, why didn't he put the very small fire out. Further, ODF may want to have a talk with your insured for using such ammunition, because as you know in our area the fire restrictions are at EXTREME during summertime and with our record temps over 100F (101F at my house today) such use of ammo could be considered negligent.

Depending where the hole is, it could also conceivable rupture the transmission housing, engine compartment, or even possibly fuel lines. This could further allow for subsequent fluid ignition. One important thing though comes to mind. In case you are unaware, both ranges here in the Medford area won't allow tracer or incendiary ammo, let alone Tannerite to be used (reference two years ago the wildland fire on the backside of the White City range was caused by the use of tracer ammo). So unless he is doing something else in violation of the state regs on such, why would he have such ammunition loaded and chambered?

Second, as I can personally attest to, .223 or similar light caliber ammunition (corelock or hollowpoint) will sufficiently create a large impact zone upon initial impact with a metal target (vehicle), and in some cases, parts of the bullet will remain in the framing member or channel. On the other side, a FMJ or AP round will leave a small impact and exit hole through a vehicle (ricocheting if it hits the block-the round is too light (55gr mass is typical round but they do come in specialty 62, 69, and 75gr loads) to penetrate.

Tracers and Incendiary Tracers can be paired up separately or together with an AP round, all of which are legal to purchase from the web at this time.

If you want more detailed information, go hit Ed Boening (30+ year gunsmith in the valley) up and ask him. He is located across from the southside Bimart/Roadhouse.

Chris