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Transplanted from old YW site:
gschwertley
Experiments with Brass Shotgun Shells - UPDATED
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Well, I've been piddling around with this project for a time and still have a ways to go.
I bought some of the brass CBC - Magtech shotshell cases in 20 gauge to experiment with. I've done some shotshell loading before, but most of my shotshells I buy store boughts now. Mostly what I do now is piddle, with 28 gauge round lead balls and slugs (you can't buy em), flechette shells, and now the brass case shells.
I think most people buy the brass shot shell cases to load up with black powder and use in CAS activities. I wanted to be able to load them with smokeless powder; problem is, there isn't any smokeless powder data out there for use with brass shells, not that I could find anyway. I decided to proceed using data for cardboard shells with similar characteristics, starting on the conservative side.
First, you must assemble the necessary components. Brass shells do not take the usual "uniwad." To begin with, brass shells are larger inside diameter and the plastic wad would be too loose. So you need to get an over-charge "nitro wad," a fiber wad to go between the shot and the nitro wad, and overshot cards to hold the charge of shot in place. You also need to get some kind of glue to hold the overshot card in place. All of these need to be oversize, to match the actual size of the brass shell case.
For my purposes in loading 20 gauge shells, I obtained 18 ga. 1/8th inch thick nitro cards; 18 ga. 1/2 inch thick fiber wads; and 17 ga. over-shot cards. I bought a jar of "water glass" (sodium silicate) at the drug store for sealing the over-shot card; you can use white glue ("Elmer's"). Large pistol primers are used.
I do all this without a shotshell reloading press. For priming the case, I stick a primer in as far as it will go, and use a small arbor press to seat it. To fully seat it, just find some small, round, flat object to stick between the primer and the anvil on the arbor press and gently seat it the rest of the way. A pin punch can be used to knock out fired primers. For tamping the wads in place, I just use the eraser end of a pencil. These cases do not need to be resized, or at least not yet in my experience, especially if fired in the same gun.
My "data" called for a 7/8 ounce load of shot, so I just did the equivalent in grains and hand-measured each charge. The powder charge I used was 16.5 gr. of Unique. First, I charged the powder, then I placed the nitro wad over it. Next, came the fiber wad to cushion the shot. Over the fiber wad, I placed one overshot card. Next, I charged the load of #8 shot. After that, I placed the over-shot card on top of the shot, and finally, sealed each one in place with a coating of water glass. I let them set and dry for a day, then marked the size of shot on the over-shot card. The result left plenty of extra brass on the end of the case, which I didn't trim because my single shot NEF that I fired them in has a 3 inch chamber. When loading these, make sure that the brass doesn't exceed the length of the chamber and intrude into the forcing cone.
The ballistic results were underwhelming. My average muzzle velocity using 7/8 oz. of lead shot over 16.5 gr. of Unique gave me an avg. muzzle velocity of 708.2 fps. with a standard deviation of 23.16. You might be able to kill a sick crow with this load, but I doubt it. As a comparison, a WW 20 ga. factory field load gave me 1174 fps. I have more work to do with this one, but at least I have made a start. I think the reason for the low velocity with a comparable powder charge for a plastic or paper case is that the plastic uniwad gives much more friction in the case (and the bore) than when "traditional" wad materials are used in a brass case.
My next work will be to increase the powder charge gradually until I approach 1100 fps. Actually, it may not take all that much more powder to reach this.
Many thanks to Ross in northern California for giving me some direction in finding the necessary ingredients for this project, although I didn't use hornet's nests for wadding.
"Sehr schwer, mein Herr"
yockey5
Hey Gary, I have a hornets nest if you want it after the 1st killing frost!
Don
Ross95966
Good show, Gary!
When plastic shot cups appeared, we had to reduce the powder charges because of the improved gas seal. It will be necessary to return to the old data to get standard results.
I used to use, IIRC, about 30 pounds of wad pressure with Hercules Red Dot in trap loads. I don't remember Unique's requirement, but it might be anywhere from 25 to 85 pounds, according to my Ideal Hand Book no.36.
Best regards from Darkest California,
Ross
gschwertley
Sometimes when I am rummaging around at a garage sale or a swap meet, I see a very old shotshell reloading manual. Usually these are way out of date as to components, so I never have given them a second glance heretofore. I now have a new outlook on the subject. I will be keeping an eye out for these old manuals so as to get data more relevant to my backwards steps in shotshell reloading.
I think my efforts to do this kind of reloading are aimed at retaining some element of independence in the future, just in case. Now that I have made a start with 20 ga., I may branch out and get some cases for .410 bore and 12 ga. I haven't yet seen 28 ga. brass cases offered, but they may be out there. Once you commit the funds for bags a wads, unless you do a lot of shooting, they will last a while.
"Sehr schwer, mein Herr"
Ross95966
The CBC 28's that I've gotten have the Berdan primer pocket. I don't know if the change to Boxer has been made yet for the 28.
I suppose they would be fine with those frail #56 primers if the gun is not wallowed out around the firing pin. I haven't loaded mine yet, after three years. I bought them up in Yreka from Dangerous Dave. Now Navy Arms is supposed to have that inventory.
At least I was able to get a box of 6,3×53 R/L before he shut the Dayton warehouse.
Back on topic:
It is reported that sportsmen loaded the brass shells in the field in the "Good Old Days" without much in the way of tools.
That fans my survivalist embers.
Cheers from The Republic of California, home of extinct grizzly bears and moribund liberty,
Ross
gschwertley
Oh, and that big jar of water glass that I bought ought to last me so long that my wife can have my casket sealed with what's left.
"Sehr schwer, mein Herr"
gschwertley
Rather than start a new post, I will update this one to keep it all together.
Summary of experiments up to mid-November 2005:
I decided to start out low and used 16.5 gr. of "old" Unique, one nitro wad, one fiber wad, one overshot card, 7/8 oz. of #8 shot, with an overshot card on top. The primers are WW large pistol, which the black powder boys use in the CBC cases. I used light pressure on the nitro wad. The over-shot card is sealed with a dollop of water glass.
At the range, I fired a string of 5 shots across my chronograph and got an average muzzle velocity of 708 and a standard deviation of 23.16. For comparison, I fired a WW 20 ga.field load and it clocked 1165 fps. The brass case hand loads were noticeably lacking in recoil compared to the field load. With this information, I decided that I was headed in the right direction, and just needed to work up the charge to get into a respectible velocity range.
This is where the experiments fell apart. My next experiments were with 18.0, 19.0 and 20.0 charges in batteries of five shots each. Here were the results:
18.0 gr:
969 fps
923
946
error
826
19.0 gr:
1042
767
989
815
857
20.0 gr:
902
649
689
832
792
Ok, so not only is the standard deviation all over, the muzzle velocities tend to decrease as they are fired in order in the test string. Also, as the charge increases, the velocity decreases. I know these are short test strings, but the trends are there. Unburned powder granules were observed in the barrel.
I have been comparing notes with another fellow who knows a bit about loading shot shells, and he suggested that my wad pressure might be insufficient to get a good burn. He also suggested that compared to the Lyman book data, I wasn't using enough wad material. With this information, I assembled yet another batch for testing. I made sure I had plenty of wad pressure both on the nitro and the fiber. Since these are hand loaded, an element of non-uniformity no doubt is there, but within my own capabilities of maintaining uniformity, I tamped in the nitro wads with a large punch and a hammer. I didn't pound them in, just carefully but using a little force tapped them in. This time, I doubled the nitro wadding (2x.125) and the fiber wadding I increased from .500 inch to .750. My test charges I decided to back down a little due to the changes. They were in Unique: 17.0, 18.0, and 18.5. The chrono results were as follows:
17.0 gr:
599 (cold barrel??)
908
796
787
705
18.0 gr:
716
793
306 (bad chrono reading?)
745
489
19.0 gr:
811
888
628
758
682
These were still erratic and nowhere near the velocities to be expected from the charges used.
So, we eliminated what we thought were possible problem areas and still have lousy results. It seems to me that somehow, I am not getting complete, sharp combustion of the powder charge. I just can't figure out why. Perhaps the Large Pistol primers used in black powder are not hot enough for smokeless powder?? The total wadding I have nearly doubled, with no doubt added friction, yet it doesn't seem to make much difference. Unique is supposed to be the most forgiving of powders, so this was my reason for choosing it. I figured that would give me a little margin of safety in this kind of work.
I should mention that my chrono is set up quite close to the muzzle of the shotgun, closer than recommended for pistol and rifles. This I do because I am not sure of the shot spread, and do not want to wipe out the chrono. Still, the velocity trends are there to see. And, if anyone doubts the velocity readings are in the ballpark, the lack of recoil rebuts these thoughts. The report made when the shell goes off sounds a little blooper-ish as well.
Update mid-November 2005:
When using Unique, the change to magnum pistol primers made no difference as to the low velocity and erratic ignition when using the otherwise same loads.
When I was loading test shells for this trip, however, I decided that I would make one batch using a powder different from Unique. For this powder, I chose another that has been listed before by Lyman using paper shells and "traditional" wadding materials. This powder was DuPont (IMR) PB, which is faster than Unique. I also used mag pistol primers with this load, but used all the same wad materials and techniques as stated with my previous batch.
The results with the Unique were miserable, but those with the PB were promising. I clocked in the 1150 fps range with 19.0 grains of PB. I will now focus on this propellant and test some more.
Two things are starting to come to me out of this. One, my Unique is old. By that I mean in years, not in the fact that it is not the "new, improved" Unique that Alliant now makes. Mine was given to me by my cousin quite a few years ago and if I am not mistaken, was made in 1974. This in itself would not make the powder bad, per se, but my cousin may not have always stored it properly. In clocking .32-20 metallic cartridge loads, I have noticed discrepancies of as much as 100 fps lower using this powder against test loads of newer Unique. So, all of this could mean that the Unique I have just doesn't have the appropriate energy content to light off properly in shotshell loads.
Secondly, when using this old Unique in shotshell loads, I can tell from the recoil that the load is weaker than it should be, so this certainly explains slow speeds. What I have been wondering about just as much, though, is the erratic performance. This has caused me to ponder on how the chronograph is reacting to the type of loads I have been firing over it, and even as to its appropriateness in testing shotshell loads. To keep from destroying the instrument, I have gotten the shotgun muzzle quite close to it, say, two feet away. This is far closer than recommended for metallic cartridges. I wasn't sure how far away I could be with the shotgun without possibly damaging the instrument.
Another thing is, when the brass shells loaded with traditional wad materials go off, the spray of disintegrated wad material is clearly visible blowing out the muzzle. It's obvious that there is a stream of material coming out the barrel, not a single, solid mass that the chrono can get a good reading on. This I believe may be why I sometimes have gotten very erratic readings. Further, I also think that this would not be so much of a problem with plastic unitary-type wads, where the payload components come out the muzzle more or less simultaneously.
I'll post more after I do more testing with the PB powder.
"Sehr schwer, mein Herr"
mikmarjon
Please do, To me this is ver interesting.
come visit us and discuss the weapons of yesterday
yesterdays weapons forums
pub151.ezboard.com/bsteyrmannlicher
yockey5
Thanks Gary, this is very interesting!!!!
coffee pot
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