‘Tis the season: range grass is drying out and fires are a concern. The latest fad is to blame such fires on those out target shooting. To support this, there is a Forest Service study of ignition by rifle bullets. It is interesting and has data and theory worth considering. Careful reading also provides insight into reality and a proper assessment of risks. For anyone with experience target shooting in the wild or with trying to start a fire without matches or accelerants, the idea that there is significant risk of wildfires due to shooting warrants a great deal of skepticism. With proper care and due consideration, target shooting in the wilds is very rarely accompanied by shooting sparked fires. The lengths gone to in the study to support the idea of shooting based fires tells you what you should not do and what is not common practice.
The study used bullets deflected off a metal plate into a bed of dry peat moss as fragments and managed to detect some smoldering with non lead bullets from high power rifles. If you’ve tried to light a fire with flint and steel, you know that such carefully prepared tinder is a must and it still takes some careful management to turn that smoldering ember into a useful fire. The study notes that ” Peat moisture contents of 3-5%, air temperatures of 34-49 °C (98-120 °F), and relative humidity of 7 to 16% were necessary to reliably observe ignitions in the experiments.” Here “ignitions” means smoldering peat, not flames.
Also consider that bullets rip and tear targets, they don’t burn, char, sear, or cauterize targets. Even ejected cartridge cases that get inside clothing don’t burn holes in the clothing nor cause any significant skin burns and those cases are where most of the combustion of gunpowder occurred.
The study looked at the energy of a bullet as if all of the energy in that bullet was used to create heated bullet fragments rather than shared with the target. The assertion is made that “The discharge of a firearm involves the exchange of significant amounts of energy” and that is relative. The data shown indicate that a .45 ACP bullet has less than 1 BTU of energy leaving the muzzle while an AR-15 round has about 4 times that. A kitchen match produces 1 BTU of energy before it burns down to your fingers. Any scout knows that being able to start a campfire with only one match can be good bragging rights as it requires careful fire building and management.
The study does provide some insight into aspects of ballistics not often considered along with tables of data, pretty pictures, and the use of some fancy equipment. The analysis also covers a lot of ground and many factors. What is missing, though, is also important as it serves to qualify the analysis and to establish a basis for its relevance to whether or not there is really a problem at hand.
The suggestions as listed in the source story on the KTVN TV news site is also worth reviewing. Don’t do stupid things, including swallowing PSA’s and rationalizations whole.