STREAK Visual Ammunition is making news.
This is nonflammable ammunition that uses a phosphor material that is applied to the base of the bullet. When fired, this phosphor material glows as the bullet moves downrange. It is visible to the shooter, but less so to anyone at increasing angles to the bullet base.
If I understand the technology, this works in a manner similar to photoluminescent sights. The phosphor material on the base of the bullet is exposed to the bright burning of the gunpowder. Some of that lightenergy is absorbed by the phosphor material that in turn begins to glow. That glow is what you see as the bullet moves away from the muzzle.
Source:: Selling the Second Amendment