Every once in awhile I think of something or run across information relevant to ammonpulver and post it. For those of you who don't know what ammonpulver is, it was the first truly smokeless propellant, it dates from the 1880s, and was used by the Austrian military in their canons and hand grenades through World War One and again by the Germans at the very end of World War Two for canons and hand grenades. It is made from ammonium nitrate and pure charcoal (yep, that's all there is to it, folks!) in the proportion of 86.96% ammonium nitrate to 13.04% charcoal but 87% and 13% are close enough, and I used 85% and 15% quite satisfactorily. For those of you who may think this is the best news since sliced bread, don't go running out and try using it because it has several severe problems associated with it. If it were the godsend it seems to be we would already be using it in everything from .22LR to .50 BMG, but we obviously aren't. The following photo is one BIG reason why we aren't. The cartridges disintegrated about 4 months after I loaded them back in 2004. After ten years I haven't dissected them to see if the IMR4895 booster charges are decomposed or if the primers still go bang after a decade, but whatever the case, they were obviously not usable just a few months after assembling the components. For those of you who have studied chemistry, what happened is not a mystery since both the copper and zinc of brass alloy are soluble in ammonium compounds by way of forming Werner Coordination Complex Ion compounds with ammonium. I knew what would happen before I loaded the cartridges, I just wanted to see how long it would take and what it would look like. When loaded fresh and used immediately, I have had good results with ammonpulver, but the necessity of having to wash your $500 rifle including all the wood to remove any highly corrosive ammonium nitrate residue and then dry it is an inconvenience that is insurmountable to most shooters. I accomplished doing that by dunking my rifles in hot water and then drying them in a large vacuum chamber at about 29 inches vacuum.
From a 2009 post I wrote at:
http://castboolits.gunloads.com/show...ht=ammonpulver
About ammonpulver, I'm coming into this thread a bit late, but maybe somebody will see it.
I did a series of very extensive experiments with ammonpulver in rifle cartridges about four or five years ago and posted the results here, they are probably still here back in about 2004, or so..
Ammonpulver is a very energetic powder with an energy content about equal to powders like 2400, Blue Dot, or Bullseye, which are all quite powerful. Its burn rate is controlled the same way as other powders by changing the grain size, and I found that the ammonpulver I made ranged in burn rate from about IMR3031 or IMR4895 down to around IMR4350 in granulations about like corn meal on down to Cream of Wheat, the finer the granulation the faster it burns. It is also flashless as well as a truly smokeless powder, the combustion products are nitrogen, carbon monoxide, and water in the form of steam; all of which are clear colorless gases. Because of the inevitable ash from the wood charcoal, a very tiny amount of smoke in the form of a colloidal dust is briefly seen, and when the temperature is low and humidity high the condensed steam is also seen as "smoke" that very rapidly disappears.
As has already been mentioned, ammonpulver is simply a finely ground mixture of carefully dried ammonium nitrate and charcoal (ammonium nitrate is highly hygroscopic and readily absorbs moisture from the air and when left out in the open it turns into a soupy puddle), the range of proportions that prove useful are from about 80% ammonium nitrate and 20% charcoal, to 90% ammonium nitrate and 10% charcoal. The chemically balanced equation gives very close to 86.96% ammonium nitrate and 13.04% charcoal (87% and 13% are close enough). However, I did all my experiments with the most commonly used proportions of 85% ammonium nitrate and 15% dead-burnt charcoal. It is of utmost importance to use dead-burnt charcoal since the creosotes left from partially roasted wood make the powder unstable and possibly subject to spontaneous ignition. The partially roasted wood charcoal that was used for canon powder by the U.S. Navy in the 1890s is probably what blew up the U.S. battleship Maine in Havana Harbor in Cuba in 1898, setting off the Spanish American War. At the time in 1898, it was rumored that a Spanish torpedo or sea mine was responsible for the Maine sinking, however later problems with auto-ignition of the so-called "cocoa powder" made using partially roasted charcoal that was still a reddish-brown color is most likely what ignited the canon powder magazine aboard the Maine, blowing it up and sinking it in seconds. Anyway, to be safe, the charcoal used for making ammonpulver should conduct electricity, ensuring that it is dead burnt and has no creosote left in it.
Ammonpulver is by far the safest powder to make, it can be repeatedly pounded with a 16-oz ball-peen hammer on a steel anvil without igniting it or detonation, unlike black powder and most other smokeless powders, and when it does burn unconfined it just barely burns. I tested this myself over and over again, and to be sure of its characteristics I even spread 100 grains of ammonpulver in a thick layer on an aluminum baking sheet in a toaster oven with a door that did not latch, and then from a safe distance I turned the heat up while using binoculars to watch through the Pyrex window in the oven door to see what happened. At about the melting point of the ammonium nitrate it finally ignited, quietly glowing orange for about 15 seconds until nothing but a tiny pinch of ash from the wood charcoal was left. I would not recommend doing that with 100 grains of Blue Dot!
I eventually tested several loads in 7.62x54R Russian, .30-06, 6.5 Swedish Mauser, and 7.5x54 French. With just a regular large rifle primer nothing happens, the bullet lodges in the barrel throat with the charge of ammonpulver behind it, making a mess in the cartridge well when I opened the bolt. In researching how ammonpulver was used by the Austrians in their canon loads, I never did find out how they ignited the ammonpulver. After finding that just a primer by itself did nothing to ignite the powder, I started out with small amounts IMR4895 over the flash hole and equally small amounts of ammonpulver on top of it separated from the IMR4895 by a thin tuft of toilet tissue to keep the two materials out of contact with one another. I fired my duplex-charged cartridges in a junker Mosin-Nagant, that rifle having been proven to be darned hard to blow up by a member here at Cast Boolits who did a blow-up test using Bullseye or a similar fast powder. Using the same rifle over and over again for the blow-up test, he never succeeded in getting the barrel to rupture or getting anything to let go violently, it finally just bent the bolt and melted the brass cartridge after several full cases of fast shotgun/pistol powder. I chose a Mosin-Nagant because of his test, and when I first fired my rifle I lowered it down a hole in the ground with a string on the trigger in case something did fly apart. I used successively larger amounts of IMR4895 and fine grain-sizeammonpulver until as I recall I had about 25% IMR4895 as a booster/initiator and 75%ammonpulver with a total combined propellant weight of somewhere around 45 grains pushing a 150 or 180-grain .311 jacketed bullet (I don't remember the exact powder charge and bullet weight, I need to look it up in my notes). I kept an eye on the primers for signs of pressure and never had anything bad show up over quite a few test firings. When I finally fired the rifle above ground, I compared performance with a standard IMR4895 load and from "reading" the depth of bullet penetration into the clay bank I used for my backstop I figured the velocity was somewhere around 2200 feet per second from the 20-inch barrel of my model 59 Mosin-Nagant carbine. I recall that the odor of the ammonpulver smoke was quite pleasant, having an odor a bit reminiscent of almonds.
I did some math on powder charges and came up with a formula I used for calculatingammonpulver loads based on cartridge length-to-volume ratios and the base 10 logarithm of the powder weight. I also need to look that up in my notes.
When I was done for the day with testing loads, I thoroughly washed the rifle inside and out in hot water and liquid dish detergent to keep any ammonium nitrate residue from rusting things to pieces, it is just as corrosive as using chlorate primers! Also, to make sure the rifle was thoroughly dried out, I made a vacuum chamber to dry it in from of a piece of 4" (I think it is 4", I haven't taken my vacuum chamber out of storage yet from moving) schedule 80 PVC plastic water pipe with end caps. I needed the vacuum chamber since I was also going to try out ammonpulver loads in my Remington 700 BDL .30-06, Swedish m96 Mauser, and others, and I sure didn't want to rust up my $600 Remington 700 BDL!
Anyway, I found out that ammonpulver works darned good in cartridges like the ones I mentioned, and when boosted with about 25% by weight of IMR4895 it behaves about like IMR3031 or IMR4895 on down to IMR4350, depending on granulation. If I ever get low on powder (a little is still needed for a booster) I can still keep on shooting as long as I have fertilizer-grade ammonium nitrate and good low-ash soft charcoal (like from grape vines, willow, avocado, or even white pine wood) available. Compared to regular black powder made with saltpeter, charcoal, and sulfur, it is extremely safe to make, as well as it leaves absolutely no residue at all.
rl576
Another old thread of interest is at:
http://castboolits.gunloads.com/show...ht=ammonpulver
rl 1,201
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