DIY Smokeless Powder - No. 7 Smokeless Powder Manufacturing

[perotter]

I see that and I wonder just how much stronger this is than the black powder substitute stuff we have been making. Obviously more, but how much more.

This would have about the same energy(power) as single base NC smokeless powder.

To duplicate the same velocity as using a store bought smokeless, one would have to refine the grain size. Mainly paying attention to the web thickness of the grains of powder, as this effects burn rate more then diameter and/or circumference.

[MUSTANG]

Screened No7 Powder 40 Mesh & Smaller

Five test rounds were loaded with the No7 Powder that had been dehydrated as previously described above. Screened to fall through a 40 Mesh Screen, resulting in particles 40 mesh or smaller. 200 Grain RCBS Sil boolit with .014 Aluminum Gas Check.

During previous shooting sessions with testing No7 Powder using heavier boolits; I was not getting readings on my Lab Radar Chronograph. I postulated that the velocity might be dropping off considerably due to the heavier boolits; so I reset the Unit to “Pistol” setting instead of “Rifle Setting”. This change allowed me to capture the velocities during testing.

Average Velocity for the 40 mesh and smaller was 1251 feet per second. I failed to reset the Chronograph for the first round, so only 4 rounds where chronographed. For some reason, this run of No7 Power was less Dense than previous; I arrived at this because the 33 Grains was at the middle of the neck of the .308 cases, where in past tests the 33 grains was at the shoulder. Had to tap each case with a spoon 10 to 15 time to get the powder to settle into the case adequately.

Low velocity was 778 fps; and high velocity was 1464 fps. Average velocity was 1251 fps. Although a smaller sampling (4 rounds), it indicates a very wide velocity spread of 686 fps between high and low velocities. Five rounds were shot on target; but only 3 were chronographed. Six rounds appear on the target because a hole patch fell off before photographing. Group size was 5 & ½”. (Vertical was 4 & ½”) There is a hole at 7 o'clock in the black; just out of the picture after it was cropped.

[MUSTANG]

Screened No7 Powder 20 to 40 Mesh

Five test rounds were loaded with the No7 Powder that had been dehydrated as previously described above. Screened to fall through ~ 20 mesh and remain on 40 Mesh Screen. 200 Grain RCBS Sil boolit with .014 Aluminum Gas Check.

During previous shooting sessions with testing No7 Powder using heavier boolits; I was not getting readings on my Lab Radar Chronograph. I postulated that the velocity might be dropping off considerably due to the heavier boolits; so I reset the Unit to “Pistol” setting instead of “Rifle Setting”. This change allowed me to capture the velocities during testing.

Average Velocity for the 20-40 mesh was 1347 feet per second (only 3 rounds). For some reason, this run of No7 Power was less Dense than previous; I arrived at this because the 33 Grains was at the top of the mouth of the .308 cases, where in past tests the 33 grains was at the shoulder. Had to tap each case with a spoon 10 to 15 time to get the powder to settle into the case adequately.

Unfortunately only 3 rounds were chronographed as I failed to reset the LabRadar for the first round; and one round failed to fire. I disassembled the “Fail to Fire” Round and it was NOT a powder issue. I was using CCI 200 Large Rifle Primers, there was a Good primer indentation – and I tried firing the round a second time resulting in an even deeper primer indentation. I bought a couple thousand of these CCI #200 Large Rifle Primers manufactured back during the “Pandemic” period and have had fail to fire with commercial powder also with those primers.

Low velocity was 1335fps; and high velocity was 1370 fps. Average velocity was 1347 fps. Although a significantly smaller sampling (3 rounds), it indicates a closer velocity spread – but at a lower velocity. Four rounds shot on target; but only 3 were chronographed. Group size was 2 & ½”. (Vertical was 2 & ½”)

[MUSTANG]

Screened No7 Powder 10 to 20 Mesh

Five test rounds were loaded with the No7 Powder that had been dehydrated as previously described above. Screened to fall through ~ 10 mesh and remain on 20 Mesh Screen. 200 Grain RCBS Sil boolit with .014 Aluminum Gas Check.

During previous shooting sessions with testing No7 Powder using heavier boolits; I was not getting readings on my Lab Radar Chronograph. I postulated that the velocity might be dropping off considerably due to the heavier boolits; so I reset the Unit to “Pistol” setting instead of “Rifle Setting”. This change allowed me to capture the velocities during testing.

Average Velocity for the 10-20 mesh was 1398 feet per second. For some reason, this run of No7 Power was less Dense than previous; I arrived at this because the 33 Grains was at the top of the mouth of the .308 cases, where in past tests the 33 grains was at the shoulder. Had to tap each case with a spoon 10 to 15 time to get the powder to settle into the case adequately. Low velocity was 1338 fps; and high velocity was 1439 fps. Group size was 2 & 7/8” (Vertical was 1 Inch)

[MUSTANG]

Thoughts on Screened No7 Powder

My observations/analysis on the Testing/Screening of the No7 Powder is that larger granules are producing a more consistent velocity and accuracy as a generalized statement. Although the 20 – 40 mesh produced an overall smaller group size (based on 4 rounds on target); the 10 20 mesh screening produced a smaller vertical measurement at a 4% greater velocity.

Target spots for aiming will have had some impact as the 20 to 40 mesh was a 7/8” target spot and the 10 to 20 mesh was a 2 Inch orange target spot. (Aim small - miss small is an old military rifle shooting saying on accuracy).

I am currently comfortable with the 10 to 20 mesh screening and the 20 to 40 mesh screening results. It sems obvious that 40 mesh and smaller is a poor performer. I speculate this is because the powder is slightly compressed, and the spread of flame through the charge of powder on ignition is not consistent between rounds, the burn/pressure curve is also potentially inconsistent – resulting in lower velocities with a much greater spread.

The 10 to 20 mesh, 20 to 40 mesh, and possibly the mixture of 10 to 40 mesh screening will provide adequate performance for recreational shooting at 100 yards and possible 200 to 400 yards which will still need to be tested and validated. Although most of us are seeking 1 - 1.5 inch groups with cast; these No7 results could improve with work – but they may not meet the performance of factory powder due to the level of consistency that a DIY Home Made Semi-Smokeless powder can be produced compared to Factory powder. But; I would be comfortable with hunting Rabbits and such out to 50 yards and Deer and Coyotes out to 150 yards with what I am getting from these tests to date.

[dverna]

Interesting posts Mustang

[MUSTANG]

Decided to take a slight detour enroute to exploring the No.7 Powder; that being trying it in the .223/5.56 case. The original .308 load data I started with was extrapolated from 8mm Mauser and 30-06 data published in the 1944 era paper that I cited at the start of this thread. I used some of the same “extrapolation techniques” for deciding where to start with the No.7 powder in the .223/5.56 cases.

Wiki lists max pressure for the 5.56 at 55,114 psi ; and for the 7.62x51 at 60,191 psi. Given no pressure signs in the .308 testing; I decided to go with the same capacity concepts used for the .308 tests; that being a powder fill to the bottom of the neck of the .223 case, same as used for the .308 case.

One reason for this Testing platform diversion resulted from Spring Cleaning of the Reloading bench and my reloading storage shelves. There were some .223 cases (Purple colored, original boxes state “for Training Use Only”) on one of the shelves that had been previously primed with CCI No. 41 primers. Since one row in the trays they were stored in only contained 9 rounds instead of ten – looked like a good place to try the No.7 Powder in during the Spring cleanup and consolidation effort. I also ran across a plastic box of 75 grain .224 bullets that I had Swaged a few years ago using 22LR brass case for jackets. These became the basis for the No.7 powder in .223 test rounds.

[MUSTANG]

I started with 18.5 Grains of the No.7 powder. It was screened to fall through a 20 Mesh screen and remain on top of a 40 Mesh Screen (20 to 40 Mesh size). I hand weighed powder for each round. The No.7 powder I have been making does not flow well . The hand weighed 18.5 grains was poured into the RCBS loading funnel placed on top of the case. Tapping the side of the funnel with a small spoon to get the powder to fall through the case mouth was the norm – not the exception. Once the 18.5 grains of powder was even with the top of the mouth; the funnel was removed, then the side of the case was lightly tapped with a spoon until the No.7 powder level fell to the bottom of the neck of the .223 cases.

I initially seated the 75 grain Swaged .223 bullets to an OAL of 2.375 inches; placing the bottom of the Flat Based bullet, even with the bottom of the .223 case Neck. After reloading the 9 Rounds; I test chambered the rounds in my Savage 12FV heavy Barrel bolt action rifle. Camming the Rifle Bolt met firm resistance. Upon opening the bolt and extracting the .223 rounds; I discovered the bullets had been further deeply seated when the Swage Bullet engaged the rifling – pushing the 75 Grain Bullets deeper into the case. The loaded 75 Grain rounds now had an OAL of 2.313 (+ or - .001) after being pushed into the case further by cycling them through the Chamber.




I will test the nine rounds loaded with No.7 Powder in the .223 on my next Range Trip. I normally swage my .223 jacketed bullets (made from 22LR cases) to a weight of 60 Grains. The 75 Grain will give me a "Heavy Bullet" comparison in the .223. I suspect that a heavier .223 bullet will result in significantly lower velocities given my impressions of what is occurring in the 30 Caliber Tests. If the 9 test rounds give any interesting results; I may conduct a follow on test where I go down in weight and try some 60 Grain Swaged Bullets with the No.7 Powder in .223.

[MUSTANG]

Test fired 9 Rounds of .223 using 18.5 grains of No.7 Powder (20 to 40 mesh); and a 75 grain Swaged .224 bullet. Rifle was a Savage 12 FV Varmint with a 26 inch Heavy barrel. The average velocity was 1593 fps. High of 1737 fps and low of 1342 fps. Velocity spread was pretty large at 395 fps between the High and Low velocities. This resulted in a 5 ½ inch group for the 9 rounds. Solid functioning; but this rifle normally shoots 1 MOA to 1 & ½ MOA with a 60 Grain Swaged .224 bullets. Distance was 100 Yards.



I believe that I have established the No.7 will work with the .223; but improving accuracy will require additional work at a later date. I am speculating that there needs to be more consistency in the powder granules; which is why the velocity spread and the larger group size.

[MUSTANG]

I also test fired five rounds of .308 Winchester loaded with 33 Grains of No.7 powder (20 to 40 mesh); and a RCBS Sil 165 grain cast boolit – powder coated and aluminum Gas Check. Rifle used was a Remington 700 ADL Varmint with 24 inch Heavy Barrel. Had difficulties in getting the Lab Radar properly aimed and was only able to get a single round chronographed, with a velocity of 1587 fps. Five round groups size was 3 ½ inches. Distance was 100 Yards.



Once again; I am going to speculate that there needs to be more consistency in the powder granules. I am thinking about in the next few weeks trying to get a dough consistency with the No.7 mixture from which I can extrude strings using a spaghetti press. These strings could then be cut to short lengths like a traditional extruded powder.

Obviously; another test with this weight boolit will be required to see if we can get sufficient Chronograph readings to use in making future assessments. This test string does seem to indicate the potential for a spread of boolit weights from 150 to 210 grains is feasible in the .308 Winchester (30-06, 30-40 Krag, and.... also?)