by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
- Not a diablo
- Accuracy
- What does stability mean?
- Conical bullet stability
- So what?
- The other hand
- Why are some diabolos unstable?
- Mechanical destabilization
- Gas turbulence
- BUT!!!!!
- Overstabilization problems
- My main point
- The take-away
As airgunners we shoot diabolo pellets without giving much thought to their design, but if it weren’t for that design our entire shooting experience would be different. The diabolo shape is what makes the accurate pellet rifle and pistol possible.
Not a diablo
Let’s start by defining the name. diabolo is pronounced de-Ah-bo-lo. It is not the same word as diablo, which is the Spanish word for devil. Diabolo refers to a toy by the same name that’s sometimes used in juggling acts. When it spins fast its two flared ends act like flywheels, keeping the device balanced on a string passing under its center shaft.
When these diabolos are spinning, they will balance on a taut string that passes under the narrow shaft in their centers.
The diabolo is the shape of our pellets, with some exceptions. The name is so universal that in many languages pellets are not even called anything besides diabolos.
The Eley Wasp is a typical diabolo pellet. It’s not that pretty but it has all the features of the diabolo design.
Accuracy
What I’m about to say now constitutes the remainder of this report. The diabolo pellet design is the principal reason that pellets are accurate. That’s important to understand if you want to shoot accurately. The weight-forward design and the high drag at the tail keeps the pellet oriented forward as it flies downrange. Just yesterday we saw good accuracy from a Crosman 760 Classic that has a smoothbore barrel. Nothing other than the design of the pellets was keeping them together as they went downrange, yet with a couple pellets they managed to stay very close together over the 10 meters to the target. Why is that important?
It’s important because the other principal way to ensure accuracy is by spinning the projectile so it revolves on its axis as it flies. Today we think of elongated bullets made of different heavy materials like lead and copper alloys, and they are so common that we don’t think of them as strange. There was a time, however, when the elongated bullet was a novel idea because until then bullets had all been spherical. A sphere doesn’t need to spin nearly as fast as an elongated projectile to remain stable.
What does stability mean?
Stability for any ballistic projectile means that it will travel along a course that can be calculated very closely. A spinning top is stable if it stands upright and remains in one place while it is spinning. Stability does not relate to the shape of the projectile, because all shapes can be both stable and unstable in flight.
Conical bullet stability
Where a round ball needs only to be spun a little to stabilize, a conical bullet needs to be spun much faster. If it isn’t spun fast enough, it will begin to move off its axis while flying and that will lead to uneven air pressures around it in flight. When that happens the bullet will fly off the intended trajectory. At close range we can see this on target paper sometimes — when the bullet passes through sideways. Let’s see.
Here you see two holes. Both were made by the same type of “collar button” bullet, but the bullet on the right was spinning out of control and hit the paper sideways, while the other one hit head-on.
I can show you a similar collar button bullet, though it is not exactly the same as the ones that made those two holes.
This is a different collar button bullet than the one that made those holes, but the shape is similar.
So what?
This report is about diabolo pellets, so why am I blathering on about conical bullets? Here is why:
Airgunners and airgun retailers persist in calling conical bullets, pellets. I’m referring to the so-called “solid pellets.” Solid they are, but in no way should you think of them as pellets, because they don’t stabilize in flight in the same way that diabolos do. They are bullets by another name, and it takes spin to stabilize them. They will be stable within a narrow range of revolutions per minute, which is affected by both the velocity at which they are shot and by the twist rate of the rifling in the bore they pass through. You can chase your tail a lot, trying to get these “pellets” to stabilize and be accurate at the distances you shoot.
The other hand
On the other hand, the diabolo will stabilize across a broad range of twist rates and, for short distances, with no twist at all, as we have seen. But I have a question.
Why are some diabolos unstable?
If you have read this blog for more than a year you have seen targets with pellet holes that are elongated. We know that pellets can yaw (tilt away from the long axis of the projectile) in flight and destabilize as they travel downrange. Why is that?
Mechanical destabilization
The most common reason for the destabilization of a pellet is when it comes in contact with something just before leaving the gun barrel. A misaligned silencer is often the reason for this. The pellet hits part of the silencer and leaves the muzzle wobbling on its axis.
You probably remember seeing the lead buildup inside the muzzle cap of the Diana Bandit pistol I’m testing. There is no way a gun can be accurate when the pellets are hitting this way.
The Diana Bandit pistol leading was actually a blessing, because the pellet was striking the back side of the muzzle cap. If it had been hitting a baffle deeper inside the silencer we might not have seen it as easily.
Gas turbulence
But the pellet or bullet may not have to contact anything to be affected. Back when I tested the Ruger 10/22 rifle for Shotgun News I discovered that putting a silencer on the standard carbine degraded the accuracy a little. It wasn’t a huge difference — perhaps a 10-shot group that should have been 1.4 inches at 50 yards would grow to 1.8-inches, or so. However, people say that adding the silencer changes the vibration dynamics of the rifle barrel, so it’s hard to say whether it was gas turbulence or harmonics that opened the group. I just knew that it got larger with the silencer on. So, I can’t prove that gas turbulence affects a projectile’s stability, but if it does then a lightweight diabolo pellet will be affected sooner and more than a heavier bullet.
BUT!!!!!
I think I have a really cool way of testing this. I’m about to test the Edge target rifle for accuracy. What if I test it first with the silencer out and then take the two most accurate pellets and test it again with the silencer installed? That will show us something, plus the way that the silencer is installed in the Edge, it shouldn’t change the harmonics at all. I will explain why that is the case when I do the test. This is something I have always been curious about and this seems like a great way to test it.
Overstabilization problems
There are obviously other accuracy problems with diabolo pellets that have nothing to do with hitting things or interference with gas. I have watched pellets spiral downrange through my scope and I know many of you have as well. This is obviously a pellet that is unstable, but it is unstable in a very consistent way. It’s almost like a baseball pitcher throwing a curveball, except I never heard of a curveball curving up. Maybe a knuckleball with control? That goes against the definition of the knuckleball. The point is — I don’t know why pellets do it and I’m not about to make something up.
My main point
I haven’t said this yet, but here is what I have been leading up to. I think the diabolo pellet design is so flexible that its accuracy potential far exceeds that of any bullet. Yes there are points at which a given pellet will be at its best — just as there are for bullets. But I think a heavyweight pellet like an H&N Baracuda Match can be reasonably accurate when leaving the muzzle of a Diana 27 at 400 f.p.s. and also exiting at 800 f.p.s. from a more powerful air rifle. You aren’t ever going to see anything like that range with bullets.
And here is why it matters. Some company will claim that their big bore air rifle gets up to 900 foot-pounds of energy, but we all know that to do it the rifle will have to shoot the longest pure lead bullet that can be loaded! It probably won’t even hit the target at 50 yards, because the heavier the bullet is, the slower it goes. And the slower it goes, the slower it spins. Yet the longer and heavier a bullet is, the faster it needs to spin to stabilize. With bullets — longer and heavier is the enemy of stability, unless there is high velocity — which is exactly what an air rifle doesn’t have!
And THAT, my friends, is why I keep insisting that we call a bullet a bullet — so the guys on their couches will wake up and smell the instability, instead of shopping by the numbers!
But our little friend the diabolo pellet gives us a warm cuddle of forgiveness, no matter what we shoot him in. I’m toying with a second experiment of shooting light and heavy pellets in a number of rifles to compare the results. I haven’t worked out all the details of such a test yet, so I will be interested in your thoughts.
The take-away
What I’m saying today is that the diabolo pellet design gives airgunners a much broader range of tolerance than bullets do. We “get away” with shooting pellets that are not well-suited to the guns we shoot them in.
Yes the diabolo design means a shorter distance, due to how soon the pellets slow down. That dynamic changes the entire shooting situation and makes 100 yards a thrilling long distance for airgunners, where for bullets 100 yards is just a warmup for the real thing.
Here is what I am NOT saying. I am not saying that heavy pellets and light pellets are equally accurate in the same airgun. They obviously are not equally accurate and, yes, certain pellets will always be the best in certain airguns. I’m just saying that with diabolo pellets we airgunners have a lot more flexibility.
B.B.,
Excellent report. Because of what you’ve written in earlier reports (but to my recollection not to the depth you have here) I think of solid projectiles as bullets (or round balls), not pellets. A pellet must have a hollow skirt.
As I read this report, I kept thinking of two items I played with as a child that depended on many of the principles you discuss, the Duncan beginners Yo-Yo, the Butterfly, which is diabolo-shaped and develops more lateral stability than the Duncan Imperial, their model that is rounder and not flared. (The Butterfly is much better suited to “walking the dog” and other ground-contact tricks, too.)
The other item I played with as a child that I kept thinking of as I read your report was the shuttlecock in badminton. The badminton racquet is more or less a lighter-duty tennis racket, but the shuttlecock, while it flies much more slowly than does a tennis ball, is far easier to direct to specific locations on the other side of the net. Like an air gun pellet, shuttlecocks have a thin hollow skirt and a weighted dome. I was not blessed with good hand-eye coordination or overall athletic dexterity, but I did quickly develop pretty good hitting technique and hit placement in badminton, all due to the design of the shuttlecock. These fascinating principles apply to so many things we take for granted.
Somewhat related, tonight I watched the 1st season ending episode of “The Explosion Show” in which Tory and Tommy visit a Civil War reenactment, and delve a bit into the history of black powder to smokeless powder, flintlocks to percussion caps, and smoothbore to rifled bore. During their exploration they shoot a lot of cool guns spanning in design from the 18th Century to the present. And of course they giggle a lot.
Again, excellent report.
Michael
Michael
I had those yo yo’s too and know what you mean. And yep badminton too.
What about ping pong and air soft guns hop up. Kind of related too.
Gunfun1,
Definitely. When a round ball spins it creates gyroscopic action which stabilizes it in flight. Furthermore, hop-up, as I understand it, can increase distance as well.
On the subject of spin and tennis, my all-time favorite player, Bjorn Borg (who I once met and chatted with for five minutes) had about the best application of fore spin and backspin In the history of the game. That was one of the things that helped him dominate on both the slowest surface, clay, and the fastest surface, grass.
Michael
Michael
Yep that too.
B.B.
Excellent report! When shooting a diabolo in a crosswind, how much of the diabolo sideways movement is because of unequal air pressures on the side of the pellet? Also, are most slugs in high power PCP’s accurate only at one speed and one twist rate?
Thanks,
Yogi
Yogi,
I think you and I said pretty much the same thing when I talked about overstabilization. Yes, I think uneven air pressure does affect the flight of a diabolo.
As for the slugs in high power PCPs, it’s been my experience that, yes, one twist rate and speed is always best, though I have very little experience with changing the twist rates for solid bullets. That’s because mine were all big bores.
B.B.
BB,
It will be interesting to see where you go with this.
The .25 M-rod baffle system has the ability to strip the air turbulence and redirecting it back in the shroud. The pellet exits and the built up air in the shroud exits behind it, again through the baffles.
The .25 Red Wolf is similar in that it uses a stripper and shroud system,.. along with a moderator. The Red Wolf shoots better with the moderator on.
The .22 Maximus shoots the best with a screw on baffle unit that is meant to go inside a muzzle mounted moderator shell. I tried a proper air stripper that also adjust, but the results were poor. The plastic baffle unit remains on to this day.
Any info. on shooting slugs is always welcome.
Good Day to you and to all,………… Chris
Chris,
I am most interested in the baffle unit on the Maximus. Picture if you can, or at least point me in the right direction. Also, was your barrel initially threaded?
RR,
Stripper:
/search-results-ext?Ntt=PY-A-4557&sid=1375A617A415&N=0&Ntk=primary&q=PY-A-4557&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch
Baffle insert:
/search-results-ext?Ntt=PY-A-7784&sid=1375A617A415&N=0&Ntk=primary&q=PY-A-7784&cx=002970863286801882398:jlcminxfwdw&cof=FORID:11;NB:1&saSearch
The gun is a Maximus Hunter which comes with the adapter permanently on the barrel with 1/2-20 male threads. You can use the cap or screw something on.
Chris
Chris,
I have one of the air strippers. I may have to pick up one of the inserts.
I kinda figured it was one of the Hunters. I will have to contact TCFKAC and see if I can get the air rifle without the scope.
I thought only the euro Maximus had a thread on the end of the barrel?
Brent
Brent,
I got it from Crosman I do believe. They had all the options at the time when PA did not as I recall. It is the Hunter version.
See comment to RR above for further info..
Chris
B.B.,
So the Collar button design is a variation of the flying dumbell? Doesn’t this also depend on the drag created by the waist for some of its stability?
Siraniko
Siraniko,
The collar button is a genuine 19th century bullet. The flying dumbell was what some people called the Balle Blondeau bullet shape.
B.B.
Any imperfection that results in the mass of the pellet not being symmetric about the axis of rotation will cause the pellet to lose rotational inertia more rapidly. Like a wheel and tire out of balance, or a spinning top with its crown off center. I suspect that sometimes the punch that pushes the slug into the swage die (during pellet production) is not centered on the axis. Any flash metal that is not cleanly parted off the skirt might have the same effect. I have thought that potting a pellet (encasing in plastic) and sawing through it to permit close inspection of the cross sectional geometry would be interesting.
I have seen a device that checks runout of the pellet as it rotates on a pin inserted into the back of the pellet. So far, have not heard any reports of using this, and I have tried to contact the company without success.
https://www.lottessporttechnik.de/produkte/joker/
Jerry and another check we should do on pellets if we are trying for the most accuracy.
BB
I’m hoping there is enough reader response to push these reports to the passing lane. So many variables correlate to accuracy for both pellets and bullets. What causes one or two flier pellets in a group of 10 when shooter error or wind don’t seem to account for the fliers? Why are some quality airguns accurate with several different pellets while others demand one or two only? These are just two of many questions I hope these reports may shed light on.
I look forward to your insight and reader responses.
Deck
Deck,
Oh! You want me to lie! 🙂
I really do not know. I wish I did. Then I could become a legend in my own mind! 🙂
B.B.
BB
You already are in our minds!
Deck
Great article.
From what I have been hearing/reading, twist rates are very important with both pellets and cast/swaged bullets/slugs. Matt Dubber has been working with FX and JSB to produce small calbier “slugs” and barrrel inserts with a suitable twist rate for several years now.
The “standard” twist rate for airguns (~1:16) is better suited for the “slugs” than the diabolo. It is my understanding that the twist rate for my HM1000X is ~1:26. Using diabolo pellets I have produced one inch groups at 100 yards. So far, when I have tried cast bullets I have not been impressed at all. Recently, many of the high end pellet pushers have changed their twist rates and improved long range accuracy with pellets..
RR
That’s exactly why I dont like predicting what a pellet of bullet will do.
As I say you got to shoot and get it on paper. That tells the truth.
GF1,
It’s a lot more funner also.
RR
Right. For sure more fun.
Gee it is about the main where the rubber meets the road gun issue and with most air rifle bore variations even the same model & production run not to mention type and depth as well as twist rate.
Then the power produced and the projectile size and not to forget the structure of the skirt as well as the head diameter. I remember not having any money and getting into it and the expenditure in pellets alone trying to find the right one and now for each gun.
I find on any gun i decide is worth keeping or rather worth the work i can find accurate pellets the problem is i need match head sizing in hunting pellets.
I dreamed last night that my bank was giving away Daisy #25s. So I went and a kindly older woman brought out 3 boxes: a newer 25, one made in mid-production and one of the first ones ever made. The guns and their boxes were in great shape. I put them in my car trunk.
In that hazy space between sleep and awake this morning I was excited about testing the 3 guns to see if they all still worked. Then I remembered. :^>
I see why you remembered that dream, thanks. I have had a dream that takes a bit of time in the morning to realize it didn’t happen.
Ah so that answers my question about FX Air Guns Hybrid Slugs.. ( stuffed into your SHOT show rpt 4… maybe aok in FX Airguns..
Dritter,
If you have a powerful .22 PCP and it is unchoked, you might want to give the JSB and H&N “slugs” a try. They may work well for you.
And I have said this before. If I go big bore its going to be .30 caliber. Not .35 or .357 caliber and its going to be a pellet, not a bullet. If it’s going to be a bullet shooting gun for me it will be a firearm. Again just the way Gunfun1 rolls.
Someone is going to know what I mean.
Here’s a hint to part of the equation. I shoot pellet air guns. Not bullet air guns.
Gunfun1
;^) Whom are you possibly referring to?
I just ordered a few thousand .177 PELLETS for my SIG ASP Super Target. I also own a number of fine firearms and understand what they are for! Lol!
shootski
Shootski
Well I would hope so. 😉
B.B.,
This is one of your most interesting reports, since it is critical to understanding the sport of airgunning.
And yes, even though I’ve been shooting airguns and firearms for years, I learned from it; thank you.
Take care & God bless,
dave
P.S. I just got to thinking, how would you classify the old original Sheridan pellets? They did have a hollow base, so I guess they are somewhat weight-forward; yet they certainly lack the wasp waist. They don’t quite seem to fit the bullet classification; yet might the fact that they are not a true diabolo be why they are not as accurate in my rifle as the JSBs which are [diabolos]?
Dave
I myself would call the Sheridan pellets slugs, or a type of bullet more than I would call them a pellet. Sort of. How about all that. 🙂
Now the next thought is would the Sheridan (pellets) actually be accurate with the right twist rate and velocity and fit to a (rifled) barrel. More so than the guns they were suppose tobe shot put of.
You never know. The Sheridan pellets might just be accurate in some kind of air gun out there somewhere. Just maybe.
Gunfun1,
They weren’t terrible; back when they were all I had, they accounted for many a squirrel. But years later, when I got some JSB 13.73 grain diabolos, they shrank my groups about in half. So, yes, those Sheridan slugs may be accurate in some .20 caliber gun out there; but for now, the old Sheridan slugs (about half a box that I have left) are sitting on a shelf, while I shoot the JSBs. =>
Take care,
dave
Dave
Go JSB.
Dave,
I though about including them, but they would be a blog of their own! I see them as mostly solid pellets, though the hollow skirt does have a lot of drag. But real diabolos shoot rings around them.
B.B.
“But real diabolos shoot rings around them.”
B.B.,
Yes, that has been my experience so far, as I just mentioned to Gunfun1 above. In fact, I got a call from my brother last night; I had given him a Sheridan over 20 years ago, and he wanted to use it on some pests, but he couldn’t find the pellets. I told him I would send him new ones that would shoot much more accurately, then I sent him half my supply from PA…I guess I’ll have to buy some more; I’m OK with that. =>
take care, and keep up the good work,
dave
B.B.,
I went back and reread some Airgun Review as well as Airgun Letters and found you have continued to learn since back then… contrary to what some millennials believe us old Dawgs can still learn new stuff!
I enjoyed todays blog as a good brush up for my return(?) to Diabolo shooting.
https://en.m.wikipedia.org/wiki/Transitional_ballistics
I have always kept it simple on Balistics so far but it is time to introduce the big guns: Transitional Ballistics!
If you all are interested, I know RidgeRunner and Chris USA are based on just today’s postings, read the linked material to get you started. Note well that it is firearm centric. It can, however, be interpreted for Airgun pressures. One final though is to note that TB is a very poorly understood and examined area compared to even our understanding of the other (TB) Terminal Balistics. As Gunfun1 would likely say it all shows up at that end and STOP trying to predict it. He won’t even like that I put words in his mouth so I’ll apologize in advance!
shootski
Shootski,
Interesting. I had never heard of such before. Well, maybe. I had heard that firearm projectiles are leaving the muzzle at such a high velocity that they “outrun” the expanding gases.
Ideallisticly with airguns, when a projectile reaches the end of the barrel the pressure behind it should be at one atmosphere. Yeah, right. This is the purpose of air strippers and such, to divert this overpressure away from the projectile, hopefully preventing this from affecting stability.
Trying to keep track of all of that mathamatitics gives me a headache after a bit. That is why I commented to GF1 that shooting and seeing is much more funner than calcumalating.
Shootski
I have said that many times and just the other day at that. Even when people was talking about Chairgun when it came out.
Ballistic calculators are just estimators. And to note I have Chairgun on my phone. It is fun to mess with. But putting the projectile on paper is when it becomes reality.
So no need to apologize. See I knew you would get me figured out. 🙂
I guess the only way to test this is choose a pellet, and an air rifle that has a wide spectrum of power levels, and shoot the gun/pellet combination through out its full power spectrum.
I would suggest the Airforce Condor, equipped with the ring lock kit, and with your choice of pellet.
You are infinitely familiar with the rifle, and I know you already have your pellet in mind.
The Condor/ring lock combination can shoot from 10meter target velocities, all the way through the maximum the condor can generate.
I really can’t think of another gun capable of shooting from 6 fpe up to 100 fpe in controlled repeatable increments.
Ian
Well now you are all just baiting someone that gets involved in trajectories as a full-time job…….
I like the idea of a diabolo pellet’s inherent stability – but as B.B points out, it is predominantly due to its weight distribution, and the shuttle-cock example is perfect. Nothing is more forgiving than a nose-heavy projectile.
Even the little Estes rockets we built as kids always told us to put the weight in the nose.
Question is, is there a way B.B can test different weight pellets that have the same weight distribution – ie, identical shape, just heavier? Where do they put the extra weight? Or will any difference he detects be due to differing distribution and not differing weight?
Second point -on the “Overtabilization” and the pellets we’ve all seen spiraling to the target. This is a projectile in precession, and that is not an unstable situation at all. You may notice that the spiraling is very regular and the pellet seems to be wandering about a central axis. There are all types of precession, torque-induced being the most likely for an airgun pellet. The challenge with precession is trying to predict exactly where in the spiral the pellet will be when it hits the target.
Imagine, however, you are launching a missile and you need to defeat a Russian-version Patriot style anti-missile defense. Having that missile spiral into its target makes it so much more difficult to intercept.
The last point- or question, is the diabolo shape’s air resistance, which is high. This greatly affects the terminal velocity of the pellet, and hence it’s energy. In a practical world, (of hunters), is there no a place for a more “hybrid-shaped” projectile that will fly flatter and hit harder.
I’ve looked at all the pellets for sale, and there seems to be at least a few that aren’t solid “bullets”, retain the nose-heavy distribution, but don’t have the pronounced waist that is part of the diabolo design.
B.B – have you ever tested any of these? Have you ever considered testing with a chronograph at the target as well as the muzzle? (it would be far easier than trying to establish real ballistics coeficients and calculating from there)
regards,
Jane
Jane,
If you post on a regular basis in the future (when applicable) as you see fit,… you will fit in here very well. We often lack a (true) technical perspective to our (most of us anyways) “armchair theories” and “ground breaking” ideas. Me included. 😉
If you have read the Blog on a regular basis in the past,… you know that the comment section can head off in all sorts of directions. To me, sectional density and weight distribution would seem rather difficult to calculate. Then again,… I am sure there is computer programs that can manipulate that data with a few key strokes and predict the results. But yes,… just as slugs are the latest “craze” (with good reason),… I think also that this is also a good time to revisit what is “the best” in pellet design.
Only a pure guess,… but I see air guns moving (in the future) to a specific pellet, specific twist rate, specific fps. Same for slug shooting air guns. Nail that down (hard) and a whole host of air guns could be tack drivers.
Like I said before,… hoping you stick around. 🙂
Chris
Rocket Jane,
Precession! Of course! Why didn’t I say that?
Well, that’s why you’re here. 😉
Have I specifically tested the heavier pellets that are still diabolos yet have some of the better ballistic characteristics of bullets? Yes, I have but not on this blog and not recently. I remember back in the ’90s when the Careers were still the hot ticket — how they loved the 28.9-grain Eun Jins and the even older Dae Sungs.
So what do you want me to do? I think heavy pellets like that need a cannon like the Condor to get them going as fast as they need to be. My Career 707 would pump them out at 70+ foot-pounds before it was modified to get more then 10 shots on a fill. That’s the kind of stuff you want to see — right?
B.B.
Jane Hansen,
There are the various deep hollow point designs that have been experimented with. But I have tried to get someone really good at casting into an area rule pellet or bullet: https://www.google.com/search?q=area+rule+explained&oq=area+rule&aqs=chrome.2.69i57j0l3.6796j0j8&client=tablet-android-lenovo&sourceid=chrome-mobile&ie=UTF-8
(The above for a quick explanation of what I’m talking about.) I believe both pellets and Airgun Specific bullets are going to see big changes due mostly to growing market pressures, not just in the USA, aworld wide.
Jane I think you need to look at some of the AirForce products and get yourself a pair of Carbon Fiber 4500psi tanks (if you have a cheap fill source nearby) and If you Cascade two say 50 cu.ft. cylinders then you will/can out of one 100 cu.ft.. of course if within your budget two 100s Cascaded is even better ;^)
shootski
Jane Hansen,
“…. Have you ever considered testing with a chronograph at the target as well as the muzzle? (it would be far easier than trying to establish real ballistics coeficients and calculating from there)”
You need to check out the LabRadar! It will report velocity at 5 different distances down range but actually stores data at PRF (Pulse Repitition Frequency.) I finally bought one after one too many downrange fatal impacts and additions to the CHRONOGRAPH Parts Bin; LabRadar is awesome!
shootski
Jane
Check out these pellets. I have used them for years. They do pretty much what you mentioned.
They fly faster and shoot flatter than other diablo style pellets of the same weight.
/product/jsb-diabolo-exact-heavy-177-cal-10-34-grains-domed-500ct?p=388
One part of the reason that these are still called pellets, even though they may be, is that they are easier to market.
Calling a projectile a pellet has a way different meaning to some than calling it a bullet. Pellet or BB guns have a way different meaning to some than an airgun. Likewise slug has a different meaning than bullet as well. So, marketing something as a bullet or slug would have a different meaning than pellet.
A number of people still refer to any airgun as a BB or pellet gun. Some still thing of them as toys. Many do not realize what technology has brought to this market, especially in recent years. Modern airguns have more energy than some firearms.
Silver Eagle
Question for all you experts,
At what point (feet per second/twist rate & so on) is a bullet/slug better than the diabolo? It get confusing to me. We had the simple BB, then the diabolo pellet. All was well. Now an onslaught of bullets/slugs that is here now and more coming. I feel like a lot of people will buy some of this bullets thinking they will work great in a reg. big box store gun. Surprise.
Doc
Doc Holiday,
Wow! That IS the IMPOSIBLE to answer question!
First what caliber? At what range? Next what performance are you after beyond simple accuracy?
I will give you my generalization. If it is small Pesting…whatever doesn’t put holes in the barn/outbuilding! So, probably pellets. Yotes, you need some range and downrange juice so .30 cal maybe pellets to 70 yards Tops, but bullets out to 150+ yards with the right rifle and shooter. Once you get bigger than that the question is thick fur/skin or thin (like White Tail) then for ethical you better go .45+ for the wound channel mostly.
Twist and FPS has formulas, readily available, that are a good starting point for that decision; since it has to do with form factor and bullet length.
it can be very confusing until you use/answer RidgeRunner’s theorem (a general proposition not self-evident but proved by a chain of reasoning; a truth established by means of accepted truths) of “what do you want to do with the air rifle/pistol?”
Trust me on this! Only then can you hope to not go down the rabbit hole of wrong airgun choice with money out of pocket and No Joy in Muddville!
shootski
Seems we’re going the same way with air rifles as happened with muzzleloaders. Muzzleloaders went from shooting round balls and conicals to shooting bullets in sabots to try to duplicate firearm performance. I’m all for experimenting and trying new things but I think you’re getting is something totally different when you talk about shooting bullets out of an air rifle. Like the muzzleloader with sabots, the air rifle with slugs becomes the poor cousin of firearms. The longer the bullet, the more you have to get to twists like 1/12 or 1/9 similar to centerfire rifles.
Brent
Brent,
B.B. and I both own .308s with 1:10 twist for a number of years.
/blog/?s=Quackenbush+.308&btnGo=
shootski
Hey Doc,
Many will disagree, but a spin-stabilized bullet-style projectile is ultimately more stable than a “front-end loaded” projectile.
Our diabolo pellets benefit from multiple features: 1. Nose-heavy, 2 high-tail drag, AND 3, they spin.
The downside of the shape is that they are not aerodynamic.
We’ve seen some nice work with airgun pellets, and Olympic-class rifles will drop a pellet into a 1/4 – 1/2 inch group at 10 meters all day. But a good 22-cal target rifle will simply hit the exact same hole, at fifty feet, and any deviation is shooter and not projectile.
I suspect that most of this is rifle and not projectile, but it does demonstrate that a good “bullet” at just above the speed of sound, stabilized at the right spin, ( around 1 in 16″) will fly perfectly straight and be impaired only by the force of gravity. Today’s sniper rifles can reach out to meter-sized targets beyond 1/2 mile using standard bullet design, and that indicates an incredibly stable flight-path.
In close, a pellet is hard to beat, but a good .22 can beat it. The pellet is going to be more disturbed by crosswinds, by irregularities in the barrel, and other environmental factors.
The rifle does need to worry about harmonics and other subtle nuances that simply don’t happen in air rifles.
Speaking only of projectiles, the bullet shape is a winner. But when you factor in all the variability introduced by the launch system, (ie rifle), I am sure there are a lot of powder burners that are amazed by the accuracy of PCPs and pellets at short range.
One thing B.B. has mentioned many times is the rifle needs to be matched to the projectile, both shape and weight. I think this is a major problem for the oddball “bullet”-style projectiles, as the barrel length, velocity, and twist was not likely designed with them in mind.
Jane,
Nice comment with a lot to think about. I however focused in on your “harmonics” statement,… more specifically,… the lack of it in air guns.
My point?,… depending on what I screw on the end of my Maximus, it will affect accuracy and trajectory. Moving the barrel band on the Maximus will do the same. The Red Wolf shoots better with the moderator on VS off. Some high end target rifles have barrel weights that are movable along the barrel length,.. no?
So,… is there “simply just don’t happens in air rifles” OR it is just that it happens to a much (lesser) degree than in fire arms?
I do not know,.. therefore I ask.
Thanks,……… Chris
Jane Hansen,
The 10meter air rifle competitions now virtually require shooting pinwheels to have half a chance of winning…that is unrested I might add!
And barrel harmonics are part of that group size improvement along with way better ergonomics and mental training of the shooters! ( Maybe of the coaches too…the mental part!)
shootski
BB, this was a great report! (or at least a great starting point for discussion)
I think that PCP’s have blurred the line between air guns and firearms (particularly big-bore PCP’s) but think that it’s a really ‘big tent’ to let us explore lots of different areas of shooting, depending on our respective capabilities (and bank account balance).
When I was much younger, I saw a military training film (B&W) that examined the ballistics of a “gun” (I think that it was a 105mm howitzer). There were high-speed films of a projectile starting in the barrel and coming down the bore (photographed with a mirror in front of the muzzle). When the projectile cleared the muzzle, I was amazed at how much movement there was. It pitched, yawed, wobbled and did things that I didn’t realize a projectile from a rifled barrel could do. Definitely a thought provoking exercise for a young mind.
I remember reading about a gentleman who described himself as a “mountain man” in the late 60’s or early 70’s, who tried to improve the 100 yard accuracy of his .69 cal smooth bore by drilling a hole in the ball and putting a six foot long ‘tail’ of high strength fishing leader on it. Said that he shrank his groups with it (but I can’t remember how small).
I remember some of the people that I met that were members of the U.S. Army Reserve Rifle Team, when they were shooting M14’s, talking about how some guns would shoot different bullet weights just fine (147, 165, 180 grain) and some took a liking to just one bullet weight and didn’t want to cooperate otherwise. The coach/match armorer just said “that is just the way they are” and that was it.
Finally, having the center of mass and the center of rotation at different places can do some strange stuff. Case in point, a “tippe top”:
https://www.youtube.com/watch?v=ItuAtgvkIkM
Thanks again, and enjoy the day.
Bill
Billj,
Ahhh…the US Navy 16″ inch rifles never did that!!!!
But only if the mount fired on the Up Roll of the BB broadside! Lol!
Interestingly, Main Battle Tanks use smoothies these days! No more rifles!!!
shootski
shootski,
Main battle tanks are quite impressive. (although I remember a joke about “A tank without a main gun is just a very heavy portable radio.”)
I am also pretty sure that there isn’t quite enough room to make a sabot penetrator round for a Crosman 760 “smoothie”.
Bill
Wow! – just like old times…
Chris USA: I used to spend quite some time following B.B and the blog, but in my work something will happen in the Middle East or somewhere, and we all put on special projects trying to figure out how they did something no one thought they could do. I get quite busy sometimes and have to drop everything.
As to harmonics in air rifles – not likely. The pellet is seeing the change in air pattern when you screw on a moderator or air stripper. Even though there is no “clipping”, the air flow can change drastically, (it can form mini-vortices, venturies, etc) and alter the pellets path. True harmonics happen after the explosion in a powder burner. That explosion really rocks the barrel, (there are some slow-mo videos), and that whipping sets up an oscillation in the barrel. That “vibration” is the barrel harmonics. It does two things – 1, because it can travel faster than the bullet, can influence its flight, and 2, it determines how well the barrel sets back down in its original place.
This is why even small 22-cal target rifles have massive, free-floating barrels, to minimize the whip and make sure the barrel settles down correctly. Does this happen in PCPs? The laws of physics tells us it does, but not to any degree we need to worry about. (probably a bigger problem in springers)
You can do a simple experiment – shoot a pcp rifle a few times, and then wrap some tape around the barrel mid-point, and try again. The tape will change the harmonics, but probably not much else.
Slhootski – Tell me more about your experience with the Labradar, everything I read said it was not good for air rifles.
Gunfun – Yes- those JSB Diabolo Exact Heavies are one of the pellets I was curious about. I need to see what’s available in .22, and .25.
B.B. YES – The old Career Infinity would launch those .22 cal / 28.9 Eunjins damn near 1000FPS and made a superb hunting rifle. That’s what I am looking for. Just the look of the Eagle Claw tells me it may do the same – clearly some of the ShinSung design elements carried over.
Best regards,
Jane
Jane
“YES – The old Career Infinity would launch those .22 cal / 28.9 Eunjins (damn: for you BB) near 1000FPS and made a superb hunting rifle.”
How accurate was that gun and at what distances? And did it have a flat trajectory? I’m thinking it probably was a no. Bet you needed to shoot that gun a fair bit of time and document some notes to be a humane hunter.
Jane,
Thank you for your perspective. I have seen those videos and to see a barrel whipping/bending up and down like that is truly a sight to behold.
My understanding of adding something to the barrel to better control harmonics,… is to have the pellet/bullet exit the barrel at the (zero whip/bend point). In other words,.. as it would if totally relaxed. In other words,.. NOT to have it exit on the up whip or down whip.
Moving the barrel band on the Maximus has nothing to do with air flow/turbulence. I ended up about 3 1/2″ back from what it was stock. Whatever it affected?,… it worked to improve accuracy.
I do agree that anything added to the end of the barrel will affect air turbulence in some manner. I also think that anything added to the end of the barrel will (also) affect the ‘whipping/oscillation,… to whatever degree that may,.. or may not be.
Be safe when abroad. I am pretty sure that “they” do not much care for the likes of us in that particular region of the world. 😉
Post when you can,… if around. If not,… we know why.
Thanks again,…. Chris
Jane Hansen,
Ah! the Internet/blog reviewers…who are they? What is the purpose of their writing? How much is typical BS!
Most of the complaints are seemingly from those who don’t understand RADAR and haven’t read or understood their Owners Manual. The first issue many users have is just getting through a proper setup; it is mostly a guy thing of not reading the instructions first! Of Not selecting the proper system trigger or positioning the muzzle in relationship to the sound pickups; or worse yet selecting the return detection activation mode. I will say that the smaller the reflective crossection of a pellet/slug the shorter the range you can expect to get multiple preselected data points. A properly aimed main lobe will detect my .25 flat based pellets at least to 100 meters (current maximum distance at my indoor range) for consistent data collection. I haven’t used my LabRadar for smaller caliber to date so have no first hand experience to share. That will change soon however all the way down to .177 cal.
Nutshell: operator skill/knowledge/expectation is the issue.
Check out these posts:
https://hardairmagazine.com/news/product-news/first-look-labradar-ballistic-velocity-doppler-radar-system/
https://hardairmagazine.com/reviews/airgun-test-reviews/using-labradar-record-airgun-pellet-velocities/
This reviewer isn’t as good as the first:
https://hardairmagazine.com/reviews/labradar-tips-and-tricks-for-airgun-use/
These folks are pretty good at what they do…not perfect but how many of us are?
shootski
I’d like to hear more about where you all think air rifles are going. The problem with moving away from pellets is the specificity that other projectile shapes require. A heavy bullet requires more spin than a light one, and changing spin involves not only twist but length, as well as power. I don’t know if the industry is going to move to rifles that really can only shoot one or two very similar projectiles.
Some PCPs have adjustable power to conserve or to suit different circumstances – each change would need a different projectile. Certainly the “ShinSung” style adjusting wheel was put there to maintain the same power as pressure dropped- but that again suggests the rifle would be good for just one “bullet”..
I wonder what the manufacturers are thinking?
Jane,
That might actually make a good blog topic because, from what I’ve seen, manufacturers don’t have much of an idea, either. The safe side is to stick with what works — the diabolo. The risky side is to try the bullet-type solid pellets. The problem is — airgunners talk a good game but when it comes to parting with cash it’s a different story. They think they know what they want, but it’s their checkbook and credit card statements that tell the real story. I will ponder it and if there is enough there I will write it.
Thanks,
B.B.
Jane
It will be a specific shooter that goes bullet shooting in a airgun.
The majority of people will still shoot a air gun as has always been. As I have said many times before. The proper tool for the job. Airguns can have many different roles they can play. Firearms aren’t as versatile as air guns. A air gun can be shot in many circumstances that firearms can’t.
To me a bullet shooting airgun is a unique airgun. Alot of time needs put into one of them to shoot them to the best performance that they can achieve. Firearms and our “normal” airguns are like that too. But I guess I will say not as difficult to get right like the bullet airguns are. Some airguns shooting pellets are dificult to shoot right. But not as tempermental as bulleit shooter’s.
My whole thing with shooting airguns are this at this time in my life is enjoyment and accuracy. I got my shoulder beat up enough over time growing up. Now I want something simple to shoot that works and fairly easily. Maybe if I was younger I would be on the top end of bullit shooting air guns. But its just not me. One of my favorite sayings is “Simple but effective”
And to round out my answer to your comment. Pellet and bb shooting airguns will always be around. Its the bullet shooting guns that is like what the .25 caliber size pellets were some years back. Very few .25 caliber pellets were available. Now look at..25 caliber. Whats got to happen is bullet shooting air guns need to become easier to shoot accurately. When that happens then bullet shooting airguns will take off.
Does anyone remember the old Oldsmobile muscle car adds of the late 60’s and early 70’s. Oldsmobile was known for there Rocket engines. They use to say “Is it rocket science” basically referring to making their cars fast in the day. And what was the answer. 😉
Jane,
PCPs can work with more than one bullet. My .308 does well with various shape weight bullets from 100 to 140gn. My .458 is very happy with various shape bullets from 310gn all the way up to 525 delivering a solid 500+FPE, MY .575 pistol and rifle do well with 283gn ball and 350gn hollow points from mrhollowpoint; as well as some others from Hunter Supply. IM still finding out more about the .58 cal.
shootski
Jane Hansen,
If they aren’t thinking spending money on basic Airgun science as well as specific R&D then they are going to see poor results on the bottom line. Airgun hobbyists are only a small part of the equation. The math and physics, as you well know, is extremely complex and beyond the effort that can be expected from BB gun shooters. The system approach has been a major step in the right direction but user/shooter educational materials/operating aides is where the real progress will be seen. The Crosman Marauder is a fantastic platform; but the user who doesn’t study and learn the adjustability features…. They will soon find themselves lost with a poorly functioning Marauder Air Rifle and a very bad taste in their mouth and hate for the manufacturer’s “poor” product. You can hear that every time a new person finds Tom’s blog looking for answers and B.B. or one or more of Tom’s Readership sets them on the path to a fix, product find, conceptually understanding the issue, learning to love airguns again!
So, manufacturers need to solve the complexity issue for the typical airgun buyer and supply the in-depth information and PARTS to the airgun cognoscenti even if it costs them short term profits to do that. The good will and the effect of the airgun cottage industry on the manufacturer’s bottom line is not to be underestimated!
Don’t believe me! Check out the current: SIG, FX, PA business models, Hard Air, and the on again off again Crosman Parts/information approach over the years.
Half of your blog basics above; I think B.B!
shootski
Gunfun1, You ask how good the old Career Infinity was – B.B. did a complete 4-part review. These are his words:
“I shot the rifle for accuracy last Friday in winds that varied from 5 to 20 mph. The wind speed increased as the shooting progressed, and even a Condor I also tested was hard-pressed to shoot under one inch at 30 yards. The Infinity did much better than that, as you’ll see.”
“One heck of a hunting rifle”..
And so I bought one, but if you read the review, you’ll see this rifle had some mechanical problems, which over time, prompted me to move to the Blizzard.
And so here’s my reason for asking about pellets with less wind resistance. The diabolos slow down quickly, so while I can get good range, I really need to know distance and get the right elevation once I’m out past 50 yards. I simply don’t have the time to get that perfected.
I only get one shot, (and a follow up for a kill if required).
Seems to me a hybrid pellet that was a little less diabolo would provide a flatter trajectory even at the same muzzle velocity, (ie -it slows down slower).
There are lots of them out there, but only the JSB seems “hybrid”. The H&N Rabbit, and Pile Driver, and the other slug-style pellets are really bullets, and a standard air rifle probably wasn’t made to spin them fast enough to provide the sole means of stablization.
regards,
Jane
Jane
That’s the thing about the JSB 10.34 pellets I posted about the other day. They shoot farther flatter and retain more energy because they don’t bleed off speeds fast because of the design of the pellet.
The faster the pellet is and the flatter it shoots and is still accurate makes for a easier shooting gun. And if you do shoot past 50 yards then you do need to test past 50 yards or don’t shoot at critters out past that distance.
And I don’t have time to read back in the report BB did. But what I have found is BB only spends a limited time on his reports. So what I have seen from shooting it takes a good period of time to really know the performance of a gun. So I say with out even reading the report that more time is needed on that gun for true results. It reality is the best I can say. You know like shooting a 10 shot group verses a 5 shot group.
Oh and most times I don’t have time to go back and look at older blogs. So if you post like you do at the bottom of the blog and not directly to me I probably won’t see it. The way I look at it is if you don’t reply directly to me then I don’t need to waste my time responding.
GF1,
You need to figure out how to get that RSS Comments on your smart phone. You can see all comments.
As I recall,… Jane’s job requires that she might be called to the Middle East (at a moments notice) to analyze the latest in enemy missile tech..
Maybe? cut her a (just a bit) of slack for not replying to you directly. In fact,… I thought that her replying to everyone in one comment was pretty smart for someone that (might?) have more important “stuff” going on. Should I ever get a plethora of responses to one of my comments,… I might follow in kind.
Chris
Yup, sometimes those smart phones ain’t so smart. I would need a magnifying glass to read comments on one anyway. I’m still smartphoneless 😉
Geo
Geo
I think you should reread your reply.
I know your a smart guy. I have seen your comments before.
Time to step it up a notch buddy.
GF1,
Okay…I re-read my reply. Seems right to me. 🙂
If by, “step it up a notch”, you mean I should get a smartphone? Ain’t gonna to happen. It’s just a simple flip-phone for me, and only then when I travel.
Geo
Geo
What do you mean a smart phone ain’t so smart.
Just as smart as a computer. And why would you say you need a magnifying glass to see it. That’s obviously a comment from someone that don’t use a smart phone. They can “blow up” the screen just like a computer or smart phone.
And I almost started a new thread at the bottom but I didn’t know how soon you would (find) the comment. 😉
GF1
Here’s the thing. Computers are used to create, and phones are used to consume. Everything on a smart phone had to be created with a computer. Guess if all you do is read email and browse the Internet, you could get by with a smart phone.
The reason I say I that I would need a magnifying glass is that my vision is impaired. My wife carries a smart phone. She needs to have one because she drives without me a lot and I want her to be able to call in an emergency. It strains my eyes just to view the screen for any length of time. Heck, I don’t even like working on laptops because things are too small. I use a 23″ monitor and still have to use my bifocals or computer glasses to read things on the screen comfortably. I also use a lower resolution so the icons and text are larger.
Then with smart phones too, I don’t want someone calling and texting me all the time. Young people don’t even want to talk, they prefer to text. Makes no sense to me. I don’t answer the phone at home unless I recognize the number.
My wife likes to play games on her phone. Recently, she said her phone was acting strangely. She took it to the phone store and they told her it had a virus on it. They could not remove the virus and said that it would have to be sent in to the factory to remove it. So, my wife ended up spending $$$$ for another phone. You sure can’t be without it for any length of time!
I use the RSS comments so I see ALL new comments, whether replying to me, or not. If the reply is to me then I do receive an email notification. But I don’t miss anything.
Have a good Sunday, and happy shooting.
Geo
Geo
I think I will look at it this way with phones or computers.
Use the proper tool for the job needing done.
Chris
My whole life requires time.
Why would you not respond to someone directly? I have a few thoughts. Do you?
That would be faster and simpler to respond right after you read a persons comment than scroll or read through all the comments to the bottom.
Your logic makes no sense.
Gunfun1,
Sometimes when using my smartphone, my replies on the blog turn into a new thread instead of replying to the original poster. It happens.
Siraniko
Siraniko,
Correct, even on a PC browser it is very easy to just post at the bottom of the posts.
Mike
Siraniko
Wow really. I have never had that happen the whole time I have been commenting on the blog. And that’s with a desk top, a lap top and several phones I have had.
But I’ll bet that is still not the case here like you mentioned.
Like right now does Jane even know we are having this conversation.
Mike and Siraniko
My last reply to siraniko ended up at the bottom after Mike’s comment. But it was not located to the left like this comment will be.
Now here’s the big thing. Neither one of you got a email notification about this reply I just made. The only way you would see it is if you came back and read the comments on this report or the feeds. Maybe that’s why no direct reply to a person’s comment. Maybe they are worried about something happening with that? That being the email notifications.
So it’s kind of like a secret comment if you will. When I comment to someone I want them to know I commented to them. Not do a search and find. Like now. When will you see this comment I made. If your not looking for it. Who knows when you would see it.
Gunfun1,
Saw it when I checked my feed. Email notification usually a few hours behind for me. I do understand that it’s easier to appreciate a direct reply to a comment but sometimes it just doesn’t get to be.
Siraniko
Siraniko
It will happen faster if you reply directly to someone than start a new comment that won’t send no notification other than the feed.
The feed is still not the same. A person still had to look when they want. Its not a notification.