Cannon Safety and Legal

Mortar Safety

Firing your mortar takes a great deal of common sense as well as a great deal of caution. Here are some safety guidelines that you should always follow:

•   At all times ensure that no one is in front of the Firing Line unless the mortar is disabled.
•   Always wear eye and ear protection while firing the mortar.
•   Always keep your Black Powder in a locked, non-metallic container.
   Always use a powder measure when loading Black Powder into the mortar--using the original container can result in a dangerous explosion.
•   Never load with spark or static producing tools or machinery.
•   ONLY USE BLACK POWDER!!! Modern smokeless gun powder may cause your mortar to EXPLODE. (Black Powder substitutes meant for muzzleloaders are the only acceptable substitute. Example: HODGDON triple se7en Easy Clean Muzzle loading propellant.)  
•   Recommended black powder is Cannon grade, FG or FFG.
•   Verify the fuse burn time.  Cut fuse to a length that will yield at least a 20 second burn time.
•   With loud clear warnings, announce that the mortar will be fired.
•   Ensure that the firing range is clear, and that all spectators are in the Safety Area.
•   Light the fuse, and return to the Safety Area.
•   Between shots, clean out the barrel and powder chamber to extinguish any residue/embers with a damp sponge. Then, wipe down with a dry sponge.
•   Ensure that no one leaves the Safety Area until the firing procedure is complete.
•   Never fire the mortar unless you can determine where your projectile will land.


The Bureau of Alcohol, Tobacco, Firearms, and Explosives, referred to here as the ATF, is the government agency that writes regulations to control things like your black powder mortar. Fortunately for us and for amateur artillerists everywhere, there is a specific exemption in the ATF’s rulings that allows us to build your mortar without fear of legal troubles. According to their rule, which is posted below, your mortar is considered to be a replica, and is therefore not something that carries any special rules or regulations on a federal level. Below is the relevant excerpt from federal laws that fairly clearly (comparatively speaking) explains that your mortar is in fact a benign replica:

26 USC sec. 5845(g) "Antique firearm.-The term 'antique firearm' means any firearm not designed or redesigned for using rim fire or conventional center fire ignition with fixed ammunition and manufactured in or before 1898 (including any matchlock, flintlock, percussion cap, or similar type of ignition system or replicas thereof, whether actually manufactured before or after the year 1898) and also any firearm using fixed ammunition manufactured in or before 1898, for which ammunition is no longer manufactured in the United States and is not readily available in the ordinary channels of commercial trade." 

Even though your mortar falls under the federal definition of a replica firearm, the laws of your state, county, or municipality may be different than federal law and have more stringent rules. It is up to YOU to know what laws dictate the construction, possession, and operation of your mortar in your area.


Butterfield Machine LLC disclaims all warranties, whether express or implied (including the warranties of merchantability and fitness for a particular purpose). Buyers and users assume all risk, responsibility and liability whatsoever for any and all injuries (including death), losses or damage to persons or property arising from the use of this product.