Gun powder on the floor


I was at a local INDOOR shooting range talking to the guys, and one of them said the following. About once a week they sweep the floor of this rather active range and broom up a sizable amount of UNBURNT gun powder. A teeny weeny amount of gun powder does not get burnt after a fired shot and falls on the floor. They get enough to fill a shoe box, and during summer dump it outdoors into a wood burning metallic barrel followed by a spectacular flame shooting into the sky. I had no idea that some of gun powder does not get burnt during shooting. The muzzle flash on Mosin-Nagant is so impressive that it is difficult to believe anything can escape being burnt. So, since this particular shooting range has 99% pistol fire, is this phenomenon of “not all the powder being burnt” a thing of handguns or all the guns including high power rifles do this “not all powder burning”?


I can not say about rifles for sure but here in Germany we had an indoor range being blown up resulting in fatalities. Unburnt powder and dust were the reason. After that (as always when something happens in the land of laws and regulations) we got a bunch of new laws on indoor ranges.


I used to get my brass in 5 gallon buckets from an indoor shooting boutique and after hand sorting all of the calibers, would have about a half of a cup of unburnt powder per bucket. Cheers, Bruce.


We use a special sweeping device for cleaning the floor of the indoor range once a week. The range is also equipped with a very good ventilation system and 2 emergency doors.

Even then, small problems may be expected. A few years ago a blackpowder shooter managed to start a fire on the range when some of the black powder residue ignited unburnt gun powder that had built up near a light fixture (in the floor).

Combining black powder shooting and smokeless powder shooting on a single range has it’s disadvantages.


is this phenomenon of “not all the powder being burnt” a thing of handguns or all the guns including high power rifles do this “not all powder burning”?

I do a lot of reloading and a lot of calibers too, I use a software program called Quick loads it is by far the best to use.

One can punch in the info about cailber, bullet weight, how long the barrel is ect. The program will tell you what percent the powder charge is filling the case and what percent of the powder is BURNED.
It will also tell you how many inches or mm down the barrel it will take before all of the powder is burnt. Many times it will show that it takes 26 inches of barrel to make a 100% burn and I have say a 22 inch barrel.

Bottom line I am surprised alot of times when it tells me only 92% of the powder was burnt. And as a side note when I have a load that is a real tack driver and very close on veloicty readings, I look up the % burnt and it is always 100% burn on these very accurate loads.
just my 2 cents


One thing that produces a lot of unburned powder and/or huge muzzle flashes are all the short carbine rifles, or even “pistol” M4 and AK type weapons which are more and more common these days. The users will often shoot typical rifle loads through these (slower burning powder), and in those cases there will be more unburned powder since the loads are designed with longer default barrel lengths in mind.


I learned the dirty way not to sweep the spent .22 cartridges into the collecting tin with the hands. Gives a metallic shine to your paws…


Always when you sweep the range after an evening of pistol shooting you get a small pile of unburned powder. Sometimes when you see pictures of pistols fired in the dark you will see streaks of still burning powder being expelled from the muzzle. Because of the burning characteristics of modern powder once they are out of the muzzle and released from the pressure they go out. So rather than unburned powder its often partially burnt powder depending on the load etc, but thats nitpicking.

this has an effect on load development with pistols using the slower burning powders. Once you got to the critical point on a load where all the powder that can be burned has been burned, increasing the powder charge after that gives no increase in velocity. All you are doing after that is adding to the pile at the end of the evening. (but don’t try this at home folks)

Back in the days of muzzle loading rifles, frugally minded riflemen would fire their rfiles over snow to assess the maximum efficient load for their rifles. Not wanting to waste scarce and, in those days, expensive gunpowder.

I would however like to expand the subject a little while we are on it to discuss the fact that close range shots to flesh leave a tattoo ring of unburnt powder around the wound, shirt or whatever . This is used by police and coroners to assess the proximity to the victim when the shot was fired. The smaller the diameter of the ring the closer the proximity. Today with modern forensics even at ranges too far to leave a tattoo ring the dispersal of unburned powder grains on the victim’s clothing can give an indication.
So its no good a suspect saying I fired at him from way across the other side of the yard, because they will know if he didn’t.


SKSVLAD, I think you will find even rifles will leave some unburnt powder. I doubt any weapon burns 100% of the powder, if for no other reason than a true 100% is very difficult to achieve in any process like this. Much of the muzzle flash on weapons is powder still burning as it leaves the muzzle. Vince is right on point, modern powders are designed to burn under pressure and unburnt powder and partially burnt powder will be a residue of essentially any cartridge fired as far as I know.




In the late 1980’s when 10mm ammo was hard to find, I “lucked” into five boxes of Hornady 10mm at only a semi-exorbitant price. I fired a mag full and noticed powder dropping out of the mag well when I dropped the mag out. I fired another eight rounds and got more powder when I dropped the mag again. Then I noticed powder on the mag follower and turned the mag upside down and shook at least a full case full of powder out of the magazine and into the palm of my hand. The Colt may have given me a stove pipe jam too, but at this late date, I can’t swear to it. There was more powder in the action and all over my shoes. I wasn’t shooting at paper so I really cant report on accuracy, but I can say that my Diet Coke cans had a very high survival rate. This was the very first Hornady 10mm that I saw on the local market. Somewhere out in the garage, I still have four boxes and four rounds. I never cared to shoot the rest and I have never bought another Hornady product.(Mainly because I am so cheap and Hornady stuff is so expensive.)
Curt Laws


I can’t add a great deal to what has been said, but I am very familiar with USAF small arms ranges, the majority of which are of a generally indoor type having concrete floors. There is a lot of unburned propellant granules to be found on these floors. There is an explosion-proof electric vacuum cleaner marketed specifically for the purpose of range floor cleaning. I have purchased two of these, at $7000 each.

What many do not realize is that under current US EPA regulations, the recovered propellant floor sweepings may constitute a regulated hazardous waste, and legally must be disposed of as such. I suspect this requirement is ignored (or unknown) by most range operators.


[quote]I suspect this requirement is ignored (or unknown) by most range operators.
[/quote]They probably do what most of us do: put a match to it ;-)


Deep in the small print of British range regulations is a requirement to mop the floors with a wet mop which I think is also ignored. Like others I always used to put a match to it.


Putting a match to it, at least in the US, would constitute an even more serious offense, namely, willful unpermitted treatment or disposal of a hazardous waste. However, as the likelihood of a typical indoor range receiving a visit from a federal or state environmental inspector is minimal, prosecutions are unlikely. But the risk exists.


Having run a range for 15 of my 25 years involved with it. And don’t get me wrong, we ran a very tight ship, straight and no messing about. But if the authorities thought that setting fire to the odd pile of unburnt powder was the only thing that happened well I don’t know. Its history now.