DIY Smokeless Powder - No. 7 Smokeless Powder Manufacturing

[MUSTANG]

The No.7 Powder in this test was screened with 2/3 of the Granules falling through 10 Mesh screen and being trapped on a 20 Mesh screen; 1/3 of the Granules screened to fall through a 20 mesh screen and be trapped by a 40 mesh screen. This was powder that has been stored in a large Vitamin Pill Jar for the last - 60 days or so. No fines (less than 40 mesh in size) were in this test mix.

Humidity was high today at 71%; so I decided to put it in the Dehydrator at 130 degrees for 1 and ¼ hours; just to remove moisture as a variable in the Testing.

Load data is mixed .308 Winchester cases, CCI number 200 Large rifle primers, 30 Grains of No.7 powder, and RCBS 200 Sil powder coated Boolit with aluminum gas check.

[MUSTANG]

Shot the 5 Test rounds this afternoon. Temperature was about 57 degrees, with a light drizzle. Target was a 7/8 inch spotter on standard 8 ½ x 11 inch letter paper; at 100 Yards.

Velocities:
1354
1341
1421
1395
1442

Average velocity:
1390 feet per second. Still 300 to 400 fps lower than my desired goal; but we will see what can be done. Looked down the barrel each shot; and the unburned kernels were a little less than when firing a commercial WC860, WC870, or WC872 powder without a "Kicker". Could look at a small smokeless powder of 2 to 3 grains over the primer to boost the ignition temperatures; but that goes against my goal of "Home Made" that meets my goals without commercial products (less the reused numerous times 308 Winchester brass).

Group size was 3 and 3/8 inches.

[dverna]

Good progress Mustang!

I hope the day never comes when making powder becomes a necessity. At my age, (73) it is unlikely; but if I was 30 years younger, I would be worried. When I was in my 40's, I would never have thought about buying a 40 year supply of powder. Things have changed.

Those who have the resources would be wise to stock up, but most people cannot afford to do that. Three pounds a year of powder is not a lot, but a 40 year supply will be 120 lbs and cost $6,000.

[MUSTANG]

My thoughts on attempting to improve the granule structure beyond screening resulted in me once again attempting to use a Spaghetti Press to make a for of extruded sticks (similar to IMR powders from the 1920’s until now). I had bought this spaghetti press a few months ago; and initially tried it unsuccessfully as the screw on cap with the holes popped out of the threads that held it in place. This was from amazon: https://www.amazon.com/Stainless-Fet...cx_mr_hp_atf_m


For this attempt to make the No.7 into “Stick Powder”; I used the above listed spaghetti press and selected the extrusion cap having 1.5mm diameter holes. I selected this cap because it was the smallest holes; and the closest size to the original IMR 4895 Stick width.

This batch has the same ratio of chemicals in the batch as previously used; with these amounts:

Ammonium Nitrate 221 Grains
Potassium Nitrate 65 Grains
Lead Nitrate 53 Grains
Charcoal 65 Grains

I wanted to limit the amount of water as previous batches produced were very watery, with equal volumes of water and chemicals used – just as described in the original manual for producing No.7 powder. I mixed all the chemicals above in a small glass jar; rotating by hand the mixture in the jar to mix for about 4 to 5 minutes; at which time by appearance it was thoroughly mixed. I dumped the batch into the middle of a Glass Pie Pan; and added 125 drops of water. I then used Auto Body filler plastic spreaders to mix the chemicals and 125 drops of water. The result was a wet black dough looking substance.


Click on Picture to enlarge.

[MUSTANG]

I placed the mixture into the Spaghetti Press; and twisted the compression crank slowly. Under compression; excess black water began to come through the extrusion holes:


Click on Picture to Enlarge

[MUSTANG]

As I continued to turn the compression crank, resistance dramatically increased. It became apparent that I was about to experience a repeat of my first attempt weeks ago where the Extrusion Cap would fail and come apart at the thread where it screws in.

I removed the extrusion cap and twisted the compression crank until a solid “Puck” of the No.7 mixture was expelled onto a Glass Pie Plate. In the picture the “Puck can be seen, and below it the pool of thick black water that was extruded before the puck was removed.


Click on Picture to Enlarge

It appears that the chemicals when mixed well in a limited amount of water actually form a thick semi-solid under pressure that will not pass through the 2mm holes I was using. The black colored water was extruded, but not most of the chemical mixture . The Puck resulting is looking a lot like what the Muzzle Loader group is producing in their thread My Home Made Black Powder: https://castboolits.gunloads.com/sho...ck-powder-quot

[MUSTANG]

My thoughts are that during the production of Nitro Cellulose (used to make Commercial Smokeless Powders since the late 1800’s – NOT USED IN PRODUCING No.7 POWDER); the cotton or wooden fibers used for the cellulose are broken down in the acid to a very small size molecularly. These small fibers are able to pass through the extruder holes in the commercial extrusion process; whereas in my experiments, the No.7 chemical mixture ( and possibly Black Powder Mixtures) are not passing through extrusion holes. The chemical mixtures do not (will not?) pass through – rather they bind together under pressure instead of flowing through the extrusion holes. Perhaps a different extrusion die set up with higher pressures might work with the No.7 powder mixture; but I am not set up for that type of experimentation currently.

At a later date; I may try an Extrusion Cap with for the Spaghetti Press with Larger holes; or perhaps one that is rectangular in shape and see if that might give a different result. Reason for my thoughts down this path are my previous experience in experiments with increased velocities and narrower pressure ranges for larger granulations of N0.7 powder. It will require some more thought and experimentation down stream.

I am currently dehydrating the "Puck" and the black water from this experiment in my electric dehydrator at 130 Degrees after this experiment. Might be interesting to see if the "Puck" when ground up will have same, less, or greater velocities and velocity spreads.

[barnetmill]

I have seen presses that were used to make larger granules for rockets and those were huge hydraulic presses. A spaghetti apparently is not enough. Hopefully what you are dealing with when moist is not pressure sensitive.

[MUSTANG]

So the Puck of No.7 Powder made while attempting to make "Stick Powder" described above completed a 24 hour drying cycle in the electric Dehydrator at 130 degrees. I crushed the puck and separated/screened it into 10 - 20 mesh, 20 - 40 mesh, and 40 and smaller mesh sizes. The amount produced after crushing for each was:


74.5 grains 10-20 mesh
110.3 grains 20-40 mesh
192.3 grains 40 & smaller mesh.
377.1 grains total screened weight

The original total weight of chemicals used in this batch was 404 grains. There was approximately 27 grains difference in weight; probably due to the materials carried with the water when compressed through the extrusion holes, and residuals inside the spaghetti press lost when cleaned.

One of the trends I have noticed in producing No.7 powder through dehydration vs cooking is a grayish color on the surface of the dried mixture. This indicates to me that one of the chemicals has a portion of the chemical being drawn to the surface by the evaporating water. Not sure which chemical it is, or if it may have some impact on the ultimate velocity and velocity spreads of the N0.7 Powder as compared to cooking it on a stove.


Click on Picture to enlarge

Previous experiments in this thread indicate that the 40 mesh and smaller No.7 "kernals" do not provide top velocity for the powder - and they produce much larger velocity spreads. Seems based on my current testing and documentation results, that we are looking at ~ 50% of the batch as having to be put into the "Recycling" container for inclusion into the next batch as it screens too small for effective use.

It may be that other techniques will produce a greater "1st time" percentage of useable powder. Comparing current and past efforts by memory is highly suspect; but my memory/gut indicates that "Cooking" the No.7 mixture resulted in harder kernels, and the % of larger grain structure was higher for batches. I will have to explore that possibility in future testing by doing one or more experiments with cooking No.7 to gather data. A harder kernel will make crushing more difficult before screening; but if it produces a greater quantity of "Acceptable" No.7 powder per batch, it may be beneficial to return to cooking.

I prefer not cooking, as it removes the risk of small particle fires during cooking of the chemical preparation. The original reference for N0.7 powder stated when cooking to keep water at hand to quench any particles that catch on fire during preparation; I used a spray bottle of water and had to do a spritz one or two times during cooking No.7 powder to put out a "Glowing" particle area in the batch. As I stated; I may investigate cooking again, and collect velocity data afterwards to see if there is a difference in velocity and velocity spread between Cooked and Uncooked No.7 Powder.

[perotter]

My thoughts are that during the production of Nitro Cellulose (used to make Commercial Smokeless Powders since the late 1800’s – NOT USED IN PRODUCING No.7 POWDER); the cotton or wooden fibers used for the cellulose are broken down in the acid to a very small size molecularly. These small fibers are able to pass through the extruder holes in the commercial extrusion process; whereas in my experiments, the No.7 chemical mixture ( and possibly Black Powder Mixtures) are not passing through extrusion holes. The chemical mixtures do not (will not?) pass through – rather they bind together under pressure instead of flowing through the extrusion holes. Perhaps a different extrusion die set up with higher pressures might work with the No.7 powder mixture; but I am not set up for that type of experimentation currently.

At a later date; I may try an Extrusion Cap with for the Spaghetti Press with Larger holes; or perhaps one that is rectangular in shape and see if that might give a different result. Reason for my thoughts down this path are my previous experience in experiments with increased velocities and narrower pressure ranges for larger granulations of N0.7 powder. It will require some more thought and experimentation down stream.

I am currently dehydrating the "Puck" and the black water from this experiment in my electric dehydrator at 130 Degrees after this experiment. Might be interesting to see if the "Puck" when ground up will have same, less, or greater velocities and velocity spreads.

The acidification step isn't what breaks down the cellulose into small particles that will flow thru a die. The step that does break them down, more or less, is the solvent step that is used later in the process, for example dissolving the guncotton with acetone.

[barnetmill]

The acidification step isn't what breaks down the cellulose into small particles that will flow thru a die. The step that does break them down, more or less, is the solvent step that is used later in the process, for example dissolving the guncotton with acetone.

correct. Nitric acid in conjunction with sulfuric acid adds NO3 (ONO2) groups to a glucose molecule of the cellulose. The higher the nitrification, the better is the resulting product.

[perotter]

correct. Nitric acid in conjunction with sulfuric acid adds NO3 (ONO2) groups to a glucose molecule of the cellulose. The higher the nitrification, the better is the resulting product.

More correctly it replaces a H2O with it. This the nitric acid does and the sulfuric acid takes away the water.

FWIW. From the best documented and available source, the original acid mix is used twice with alteration. The 1st time one gets a 13.x% NC and the 2nd time gives an 11.x% NC. These are combined to give a 12.1 to 12.4% NC.

Then the acid mix is fortified to be used again. If memory serves, the Germans and apparently most removed some of the water from the mix to give the same original strength acid mix. The acid could be reused about 6 more times for something like 14 separate nitrations. After that the acid either went thru a more complex recycling or was disposed of. The Brits used a different method of recycling, but it overall was more resource intensive.

As one can see, making a NC for standard smokeless powder is fairly cheap. As cheap as making blackpowder. But making the smokeless powder one wants repeatedly is the hard part. Given during WW2 something like 1100 different nitrations where used to make a single batch of powder and then that was used with several other batchs to make a single lot of powder they still ended up with lots of powder that was to slow or to fast for use in the mil spec ammo.

IMO about the safest route to use a DIY NC smokeless for full power rifles is to it as an additive to AN. Then the variation of the NC smokeless would have less impact. DuPont during WW1 came up with using NC powder as the binder and fuel for an AN based powder. I tried that a couple of decades ago but used store bought NC lacquer. It worked well even with a lower than desired nitrogen content. Also worked fine with NC based ping pong balls, but only when I gave the cut up ball a kwik rinse with acetone to remove some flame retardant.

Please keep in mind that DuPont at the time didn't know how to overcome the phase shift of AN like we do today. So I wouldn't recommend doing what they did exactly and I'd add the desired amount of KNO3 to it.

[perotter]

Given that AN is dissolved by menthol alcohol(other alcohols?) one might consider replacing some of the water with that when using the using a no-cook method. In couple unrelated industrial processes I've used 10-20% addition of alcohol in the water greatly reduced drying time even when just left in a room to dry.

[MUSTANG]

Given that AN is dissolved by menthol alcohol(other alcohols?) one might consider replacing some of the water with that when using the using a no-cook method. In couple unrelated industrial processes I've used 10-20% addition of alcohol in the water greatly reduced drying time even when just left in a room to dry.

This is interesting. I have been considering exactly this as an experiment for making No.7 powder over the last couple of months. I keep a dozen or so bottles of 70% Denatured alcohol (sourced at Costco or WalMart) for use in starting the wood stove that heats the house in Fall, Winter, Spring. I still have the old Boy Scout fire starting skills with a single match and no accelerants; but the wife wants that fire going and going now in the mornings when the weather cools down.

I may try the 70% isopropyl in the nest few weeks, and also the 91% Isopropol Alcohol (Walmart Equate Brand) to see how that may affect outcomes. Found these difficult to come by in the last not to be named Virus Scare when shortages hit the shelves; which is why I keep a dozen bottles of 70% on the Closet Shelf in the bathroom. It's cheap enough to by and store a couple dozen bottles for fire starting and powder making if it should prove beneficial. Wonder how Bacardi 151 would work out?

[MUSTANG]

...

IMO about the safest route to use a DIY NC smokeless for full power rifles is to it as an additive to AN. Then the variation of the NC smokeless would have less impact. DuPont during WW1 came up with using NC powder as the binder and fuel for an AN based powder. I tried that a couple of decades ago but used store bought NC lacquer. It worked well even with a lower than desired nitrogen content. Also worked fine with NC based ping pong balls, but only when I gave the cut up ball a kwik rinse with acetone to remove some flame retardant.

Please keep in mind that DuPont at the time didn't know how to overcome the phase shift of AN like we do today. So I wouldn't recommend doing what they did exactly and I'd add the desired amount of KNO3 to it.

Mixture already has KN03, so perhaps adjustments may have impact.

I have had a parallel thought for a couple of months that down stream I would attempt to make some "Gun Cotton", and use it as an additive to the No.7 powder. This thought was further fueled by the current No.7 powders with a 200 grain boolit not achieving velocities much over 1400fps. Adding enough "Gun Cotton" to get velocities to 1700 to 1800 fps with that RCBS 200 Sil boolit in 308 Winchester will be the subject of some cogitation over the next few weeks/months. Obviously; those potential/possible/probable "Pressure Spikes" will be constantly in mind as modifications and experimentations continue.

[MUSTANG]

Once again; not being a chemist - Thought it might be beneficial to "Look Up" the difference between Methanol and Isopropyl alcohol.

Methanol consists of a methyl group (a carbon with three hydrogens attached) connected to a hydroxyl group. The formula is CH3OH.

Isopropyl alcohol, also known as isopropanol, consists of an isopropyl group–this can be described as two methyl groups attached to a carbon–bonded to a hydroxyl (OH) group. The formula for isopropyl alcohol is C3H7OH.

The additional carbon and Hydrogen content in Isopropyl is readily visible in the Chemical Formula; not sure how their actions may affect the No.7 powder.

[perotter]

Mixture already has KN03, so perhaps adjustments may have impact.

I have had a parallel thought for a couple of months that down stream I would attempt to make some "Gun Cotton", and use it as an additive to the No.7 powder. This thought was further fueled by the current No.7 powders with a 200 grain boolit not achieving velocities much over 1400fps. Adding enough "Gun Cotton" to get velocities to 1700 to 1800 fps with that RCBS 200 Sil boolit in 308 Winchester will be the subject of some cogitation over the next few weeks/months. Obviously; those potential/possible/probable "Pressure Spikes" will be constantly in mind as modifications and experimentations continue.

Years ago when I first saw the N0. 7 powder the first thing I looked for was if it had enough KNO3 in it to stop phase shift (one part KNO3 to 9 parts AN good between about -32 to +200), which it does. Otherwise I would have mentioned the dangers of out having it in a mix right away. There are other things that prevent phase shift, but KNO3 is easily available and serves as a burn rate accelerator.

One might consider using cotton linters or at least cut up the cotton into 1/16 or 1/8 inch lengths instead of using cotton balls like most/all I've seen on youtube. There are reasons the industry uses short lengths beyond the raw product being cheaper. In an ideal world they would all be the same length.

If one did make or buy some NC, I'd suggest giving the 'Polarization Liquide Method' of Liptokov some consideration of use. It's a both a good way to remove any left over acid that is in the NC and convert the NC into a denser product. The left over acid is what caused WW1 era powders to degrade so soon after being made. His video on doing this is on youtube again and his channel is 'Labatory of Liptokov'.

The details of his video is good enough to provide the info one needs to not only purify it, but to make something along the lines of the old Marksman powder(I think that was a low density powder). With what I had-I'm a bit frugal and didn't want to buy lab grade ethanol- and as denatured didn't seem to work at all I used 190 proof Everclear- and using a 12.4% NC I had to change the amount of acetone to get a Marksman sized powder. I assume that with a DIY NC, one might have to also alter that if particle size matters.

One nice thing with his method when the size isn't right, one can fully recycle product back again for reuse in the next batch.

FWIW, the Marksman sized powder I made worked, but tested for a lower FPS and a 93 gr bullet without any pressure or accuracy testing. Also in the last 4 or 5 years of testing it hasn't degraded, but it is a small amount. It does of course pick up some moisture from the air in the summer, but it dries back out in the winter. Seems no different than the 4064 that I also keep on my desk to do comparative testing with.

Sorry for the long added on about my experience with the Liptokov process that is outside what you are currently doing.

[barnetmill]

One thing that I will recommend for people doing such adventures is to do them in a separate structure from the primary living quarters and the have walls that will not rigidly confine an explosion. Be very careful not to use sparking tools and especially in the winter take measures against static electricity. Absolute removal of residues is essential from the building. One plant I visited would washout the nitrocellulose fines to a near cow pastures where nature will take care of it. Field mice in powder buildings have been said to have made nests out raw nitrocellulose.
I understand that what is being made is different than nitrocellulose, but caution is very important.

[perotter]

One thing that I will recommend for people doing such adventures is to do them in a separate structure from the primary living quarters and the have walls that will not rigidly confine an explosion. Be very careful not to use sparking tools and especially in the winter take measures against static electricity. Absolute removal of residues is essential from the building. One plant I visited would washout the nitrocellulose fines to a near cow pastures where nature will take care of it. Field mice in powder buildings have been said to have made nests out raw nitrocellulose.
I understand that what is being made is different than nitrocellulose, but caution is very important.

NC has long been stored in a water/alcohol mix. Safe enough that even gunpowder grade is shipped without any haz mat charge etc.

[barnetmill]

NC has long been stored in a water/alcohol mix. Safe enough that even gunpowder grade is shipped without any haz mat charge etc.

But if it gets dried, then you have problems. When are working with energetics I am advising a lot of caution. I seem to recall a pyrodex explosion some years ago that also killed its inventor. These things happen I am not saying not to do such, but only to be safe when doing it.
Never let your home insurance know about it for sure.