Air Venturi Dust Devil Mk2 Frangible BB: Part 3
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- The first and best test
- Test strategy
- Crush test
- Test 2 — close impact
- What have we learned?
- Hard target test
- What does this tell us?
- One last test
Today we look at the frangible properties of the new Dust Devil Mark 2 BBs. Remember — these are the only Dust Devils you can buy and the box does not say Mark 2. But the BB I am testing is what you can buy and all that you can buy!
The first and best test
What I show you today is the first time I have tested Dust Devils at all. I did shoot the Mark 1 Dust Devils against a concrete floor with nothing remaining and no bounce-back, and at the 2018 NRA Show where Pyramyd Air always runs the airgun range, Dust Devils were the only BBs fired and there was not one bounce-back in perhaps 10,000 shots. Today I will take it several steps further.
I reasoned that I am interested in the low threshold of the BB’s performance. If they work at slow speeds they will also work at higher speeds. So — what is the weakest BB gun I own? Well, overlooking catapult guns like the Daisy 179 and the Johnson Indoor Target gun, the weakest BB gun in my possession is my Daisy 499.
The new Dust Devil is slightly slower than the older version. A 499 that shoots a conventional Daisy BB at 232 f.p.s. shoots the new Dust Devil at 237 f.p.s. So it’s comparable.
So — how do I test them? I had initially thought of shooting them at my concrete garage floor, but then a more involved test plan formed in my mind. Let’s see what I did.
In any test you should always try to practice-test the item if possible first. With some things like atomic bombs that proves impossible, so you test each of the components, subassemblies and assemblies, seeing how closely they adhere to your projections. But there were physicists in the Manhattan Project who predicted that the reaction of the first atomic bomb would not end with the destruction of the fissile material but go right on exploding every atom in its path and destroy the earth. Where do you stand to test that? It may seem funny now but before the first test it was nothing of the kind.
The Dust Devil is different. It’s possible to test them without shooting them, and that’s what I did first. I put one BB in the jaws of a pair of common household pliers and held it over a clean sheet of paper as I squeezed. It took less energy than I expected to make the BB burst apart, and when it did it sent dust flying everywhere. Some of it hit me. I also heard one larger fragment hit some thing in my office.
I guessed that one-quarter of the BB’s mass remained on the paper. A Dust Devil Mark2 weighs 4.6 grains and I weighed 1.2 grains of dust from the paper. That’s just over a quarter the weight of the whole BB.
Test 2 — close impact
Next I went into the garage to test the BB against a hard target. I didn’t use the floor this time because there was no way to control the remnants or to gather them after the impact. Instead I used a deep box with a white styrofoam sheet on the bottom. Anything that stayed in the box after impact should be visible on the white sheet.
Inside the box I put a plate of 10-gauge steel. I shot the 499 at that plate from 2 inches away. The BB shattered completely and became invisible. I did hear one larger piece hit elsewhere in the room, so there was some bounce-back, though I’m sure it was very small from the sound it made.
I figured some of the BB remnants would be on the white sheet, and they were, but when I removed the steel plate from the bottom of the box, I felt a small piece of the BB that had fused to it. I carefully removed it and photographed it for you to see.
The small piece of a BB on the left was fused to the steel plate, when fired from a Daisy 499 from 2-inches distance. This photo has also caught the whole BB on the right perpendicular to its band that now looks like a shiny halo above it.
This is a little over a one-inch square section of the white foam after shooting at the 10-gauge steel plate. The entire bottom of the box looks like this, except the larger pieces like the one near the center of the photo did not travel as far from the plate.
What have we learned?
I think these tests have revealed a couple things. First, that the Dust Devil tends to hold together until it doesn’t any longer. It doesn’t flake apart slowly — it explodes. Not from any force from within, but from holding together until it can no longer stand the strain. That makes it very safe when it comes apart. But you need to know that larger pieces do come off the BB and you need to wear eye protection the same as you would for regular BBs. You probably will never be hit by a particle that causes pain, but from time to time you or someone in the vicinity will feel some larger pieces come back.
The second thing we have learned is that it doesn’t take much force to break up a Dust Devil. That is in the advertising, of course, but my two tests demonstrate it quite well. However, that begs a question I have not yet asked. What is the definition of a hard target?
Hard target test
The last test I did for this report was to try to determine what constitutes a hard target. The steel plate obviously is hard, but what about a tree with thick bark? I would think that is not a hard target because the bark is softer and does give a little. How about a lightweight steel spinner? Where does the “hard” in a target begin?
For this test I used a small steel can of the type that green beans might come in. I placed it inside the box, standing it up so the bottom of the can was presented as a target.
This time I held the muzzle of the 499 about 12 inches from the bottom of the can. I had no idea of what to expect, except I knew that the can would give just a little to a regular steel BB.
The Dust Devil hit in the center of the can bottom, denting it slightly, and the BB bounced back out just a little. It came perhaps 2-3 inches above the top of the can, but landed inside the box.
I was surprised to see the Dust Devil apparently intact, except when I looked at it closely I saw a frosted area on one side, where the BB’s shine had turned dull.
I took the BB to my office to examine it under a 10X jeweler’s loupe. When I did I saw that the frosted area appeared to be the particles in the BB, just as they are coming apart.
This is difficult to see and even harder to photograph. Look at the BB band at the top in this picture (arrow). See how it is frosted, not shiny like the spherical portion below? I believe this test has captured a Dust Devil just before it explodes into dust.
Apparently the can that was slightly dented by the BB provided just enough slowdown for the low-velocity BB that we captured a very rare phenomenon. We have a frangible BB that has been brought to the brink of destruction but still remains whole.
On the opposite side of the BB there is a very small dent that I have never seen on a Dust Devil. Not only is it a dent, but around the side the material is raised, as if the material within has been displaced. I think this is the opposite side of the shock wave that passed through the BB on impact.
What does this tell us?
This time the entire BB bounced back — BUT — the bounce-back wasn’t very fast. I believe the BB’s energy was absorbed by both the slight dent in the can as well as the near-destruction of the BB, itself. This was a chance happening and nothing to bank on, but it does answer that other tricky question about what makes a target hard.
When you shoot Dust Devils, protect yourself and others in the area the same as you would for conventional steel BBs. But you can shoot at hard targets with BB guns, which is something I would never recommend doing with conventional BBs.
Targets will range in hardness all over the place from very hard to marginal. If you protect everyone in the vicinity, the Dust Devil gives you a safer way to shoot.
One last test
Since these little critters are so friendly and safe, do they work in a full-auto BB gun? Now I know that they do because Pyramyd Air was shooting thousands of them in Crosman DPMS guns at the NRA Show. But I said I wanted to test them this way too and since I own an Umarex MP-40, I thought, why not?
Well, I tried but my MP-40 wasn’t cooperating. I loaded two fresh CO2 cartridges into the magazine, and if I tap the valve stem the mag does fire. I was able to get the gun to shoot a couple shots full auto when I held the trigger down and released the cocking handle. Yes, the selector switch was set in full auto. It’s something I need to sort out. You see, BB has the same sort of problems as everyone. You just hear about it when they happen.
This is the first good hard target test I have given the Dust Devil, and it is the Mark2 version that was tested. The BB seems to perform as well as anyone could hope for. You still should take every precaution you always do when shooting any pellet or BB gun, but if you do we now we have a BB that won’t shoot your eye out.