Depending on the round, the tracer will burn out to 400-800 meters. In flight the bullet has a tail of VERY hot flame extending a couple of feet behind the bullet.
Smokey the Bear must have a wanted poster out for me, I have flamed so many military firing ranges (Hey- 8 belt fed guns on the line, firing 5-1 ball tracer, or APIT, that is a LOT of flame.
However- OUR ranges were constructed in the expectation that we WOULD set them alight- firebreaks plowed around permimeters, limited combustibles, etc. YOUR shooting area may not have that, and under State law, if YOU start a fire, YOU are responsible for damage, AND the cost of putting it out.
3 years ago, had to do a tech investigation of a boo-boo involving a munition that went beyond expected boundaries of a test area. Total $$$- 2.5 million for putting out fire. $5 million for the ranches that were burned down.