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.