The bullet would just about have to strike stone or metal to make sparks. The chances of a fire starting that way strike me as rather small.
A modern jacketed bullet is composed of a lead core covered by a copper jacket. Neither lead nor copper will produce a spark no matter what you strike them against.
A tracer round, on the other hand, literally burns. That’s what makes it so bright. They are so damaging to a good bore however, that a serious shooter is not going to ruin his rifle for a few minutes of “fun”.
Mechanics use copper and brass tools whenever they are working in dangerous, explosive conditions precisely because they don’t throw sparks.