The secret behind JSB accuracy
I think I made a huge discovery, I think I found the secret behind one of the most accurate pellets.
It all started when I was playing with a JSB pellet and going nuts asking it why are you so straight? It then jumped out of my hand and fell hitting the floor, hard.
I picked it up and to my amazement I found the skirt on the pellet bent it’s strange how soft these pellets are, a bit too strange. I did a finger nail test on the pellet and I can scratch it pretty easily, I tested other cheap pellets and they were alot harder than the JSB.
I tested some pure lead that I had and it was harder than the JSB pellets.
I think that the JSB are made of a lead-tin alloy, just like the alloys they use for soldering.
Sure the pellet dimensions are important for determining accuracy, but I think that’s what makes JSB pellets unique.
What do you guys think?
All Replies
LEADBETTER,
I know about those bullets. As you said though, ITS a “COPPER/TIN MIX” and not PURE TIN. And it compressed powder core and NOT Solid Cored. Upon impact the bullets literally disintegrate or explode but NOT mushroom.
David.Solomon,
Here:
Common Bullet Alloy Hardness
Alloy BHN
Lead 5
WW (stick on) 6
Tin 7
1 to 40 tin lead 8
1 to 30 tin lead 9
1 to 20 tin lead 10
1 to 10 tin lead 11
WW (clip on) 12
Lead Shot* 13
Lyman # 2 15
Water quenched WW 18
Linotype 18 – 19
Monotype 25 – 27
Oven heat treated WW 30 – 32
Antimony 50
Lurker, you going to share that popcorn, or do I get my own? :party:
:popcorn:
I have seen a device similar to the one in the Utube video’s being used to test gold jewelery in Pawn shops.
Tedd, don’t fire lap that barrel until you see how it shoots.
Hoot is spot on the different variables for a pellet to shoot accurately in an given barrel. But there are also other problems that rise up, ie when they change dies and then those wonderful JSB’s that shot so well now have a different head size and no longer shoot in the barrels as well as the last batch. Another case in point is the serious target shooters lusting over different Crosman brown box pellets and their die stamps.
Which is just one of the many reasons I started shooting cast bullets in air guns, I can control the alloy and the size of the projectile to match my barrel, as a result my air guns shoot better and I am not held hostage to ammo makers and their expensive pellets.
Steve, your certainly welcome to bring a beaker of water over to Charlies’ and see how far your sample raises the water in his beaker. Oddly enough, perhaps it is because like you infer, I don’t get out enough these days into the real world, 😛 I personally would not base my alloy purchases on your density tests.
And if that density test is so accurate Charlie, why bother with Google or your close friends mass spectrometer?
Now about tin. I purchase pure tin and add it to pure lead, or so the folks who sell it to me, Rotometals, say it is pure. What the tin does, is help the molten alloy fill the mold better, or as us casters say, give a better fill.
It does make the bullet slightly harder, but if you want a truly harder bullet, add antimony to the lead tin alloy, you get something on the order of Lyman #2 alloy, which I have many pounds of, and use it with pure lead in a mix of 75% pure lead and 25 % Lyman # 2, in certain molds this give me a more accurate bullet.
In air guns, a hard bullet is not a asset as it is in firearms, we just do not have the energy to take advantage of the harder bullet and the additional forces needed to propel it out of our barrels is simply an energy drain.
But I am speaking of cast bullets not pellets. My FX Royales shot better as single shots, due to those pellets deforming in the magazines as Leadbetter suggests.
In swaging, which I did for 30 years with Dave Corbins equipment, I cast cores of pure lead, and various alloys up to and including straight wheel weights, all it did was make the swaging process more difficult, but I was after better penetration in the .223 cartridge. I found better penetration not thru harder cores but thru an additional annealing step for my jackets. The best route was to buy lead wire and use a core cutter, which I did often.
Steve, the older guns did not shoot nearly as well as the new guns we have today with factory ammo. Accuracy of barrel makers and their equipment was not nearly as good as the consistent products produced today.
Most older ammo was made undersize, that allowed it to fit in everything out there. Black powder was relied on to bump up the projectile to fill the lands and grooves, early smokeless military cartridges were always suspect in accuracy due to the undersized bullets, and of course due to the corrosive primers they used destroying the barrels in one outing.
It is said by the old timers that for a while in 22 rimfire production, you could not get home quick enough to clean your barrel to save your barrel from the effects of the corrosive primers.
One exception to the rule was when black powder cartridge shooters started exploring the science of the 1880’s, the results were dismal, the powder fouled so bad you could not keep your shots on a 4×8 piece of plywood at 100 yards, the fouling was finally solved by Steve Garby with his SPG lube.
My objection to this entire thread is the author saying he has made a earth shattering discovery in that JSB’s shoot better because they are soft. 🙄
He wanted our opinions of his discovery, and my opinions is thus:
Give me a break, I get enough of this on my boots in the sheep pen..
RC
Hoot I agree with you completely. The idea that started this thread is not the accuracy of JSB specifically but rather tring to understand or take in consideration the hardness of the pellet when talking about accuracy.
I see alot of talk about head size, skirt size and the ratio between both and how it affects accuracy. And it seems that different brands make pellets with the same head size, skirt size and profile but still they shoot differently.
It must be the hardness of the pellet, again I am not sure how adding tin would affect the hardness but I have noticed that JSB pellets are a lot softer than other brands.
Well said Hoot, 🙂 I’ve noticed that crossman pellets will shoot well though repeaters that some jsb pellets Would not. Do you think that the harder pellet is not affected by misalignment from the magazine to the chamber in some rifles? Or is the relatively shallow groove of most airgun bores better paired with the harder pellets???
The true answer to pellet accuracy is not likely to be as simple as lead content/brand name. Rather, I believe it is a combination of a lot of factors.
One point not yet made is not all rifles shoot JSB pellets as well as they do other brands. The Benjamin rifles tend to prefer Benjamin pellets over JSB…at least that was my experience with the three Marauders and four Prods I owned and modified. This experience seemed to stand out with the .25 caliber barrels. The Benjamin pellets are quite hard, but the Marauder’s stacked them time after time.
Ed, of Edguns, has designed his pcp’s around the JSB pellets, down to the twist rate and type of rifling…and has had LW modify his particular barrel designs to maximize accuracy…thus springs forth the excellent accuracy results with JSB pellets in Edguns.
I don’t find this experience totally true of all pcp rifles. I had excellent results with Barracudas in my AA rifles. At least as good as JSB products. The slope angle of the domed head design seemed to play a part as well.
In short, I believe overall accuracy boils down to the specific pcp barrel design, maker, fps/fpe achieved, twist rate, pellet weight, pellet design/shape, down to microscopic detail, and metal content. When taken in conjunction with all the prior factors, it has not proven any one pellet provides maximum accuracy all the time.
Tried, tested, and found true…you get a pcp, and start testing to find what pellets work best in that particular rifle. And, from what I’ve read over the years, even the same brand/type rifle may vary in it’s particular pellets of choice for best accuracy.
Consistently accurate projectile, and rifle combinations, are like eagles…they don’t flock. You have to search them out, one at a time, until you find one that consistently works for you.
Then, the best advice is to stick with what you personally find to be effective, and put up with the occasional inconsistencies that impact your choice from time to time, for no readily apparent reason.
That’s my experience…not everyone will agree. That’s ok.
H 😯 😯 t
this
https://www.youtube.com/watch?v=OP4zc33-ctM
will do the trick to i guess
RC
I did some searchin before posting and I found this post :
“Hi, guys: Besides making the groaning noise when bent like Finn45 said, tin reacts with hot concentrated lye water to make bubbles and a white insoluble residue. Lead doesn’t do that. If you make some lye water for a test, only make a small amount and wear eye protection. Lye gets hot and will explode when water comes in contact with it, so when mixing a solution be very careful! Also, tin never tarnishes and is always bright silver colored and shiny, while lead is dark and grayish colored except when first cut, but it turns gray in a few days. Lead is soft enough to be dented with your fingernail but tin is not. Unfortunately, when you find these metals they are usually alloyed, which covers up all of these identifying properties. Zinc also makes a crackling noise when bent, but it sounds different, more like breaking toothpicks. Zinc is a dark bluish-silver colored metal and is never shiny except when freshly cut.
To determine the approximate amounts of these metals in lead-tin alloys is pretty simple with a reloading scale. All you need to do is weigh a small piece then weigh the same piece under water and find its specific gravity by dividing the dry weight by the difference of the dry and wet weights. Lead has a specific gravity of 11.34 and tin has a specific gravity of 7.31, and using the following method the percentages of each in the alloy can be determined. Using the formula of:
x/spec grav lead + (1-x)/spec grav tin = 1/ spec grav of alloy. To find the percentages of lead and tin solve for x. Let’s say that the specific gravity of the lead-tin alloy is 9.15. Then x/11.34 + (1-x)/7.31 = 1/9.15 Turning the math crank we now get 0.0882x + 0.1368 – 0.1368x = 0.1093. Combining like terms we end up with
-0.0486x = -0.0275, then solving for x we have x = -0.0275/-0.0486 or x = 0.5658, which translates to 56.58% lead and 43.42% tin. We know that the lead is 56.58% and not 43.42% because the lead specific gravity was used as the first value in the sequence of operations in the formula. Because of that, make sure to get the sequence of operations right so that the correct value gets assigned to the correct metal. I hope I didn’t make any typos, I looked it over, and it seems okay. For those of you with an electronics background you’ll notice that the formula is the same one that is used for finding resistance values for resistors in parallel!”
Google is useful
Oh and by the way I have a friend with access to a mass spectrometer and a NMR
“Pure lead is undesirably soft for casting bullets not requiring such expansion. [Tin is a common alloying element. “Lead alloyed with a small amount of tin fills out moulds more uniformly than pure lead. Tin also increases the hardness of cast bullets up to a maximum at about eight to ten percent tin.” Tin is relatively expensive, so many modern alloys rely upon antimony to increase hardness while retaining the casting advantages of a minimal addition of tin. Linotype metal is a eutectic alloy………………..
I have shot PURE TIN PELLETS and they are super light and SUPER HARD.
No amount of testing on your part is necessary, TIN is HARDER than Lead. That is just a fact.
Why do you think in the HISTORY of ammo making that no manufacturer has made a TIN cored bullet or even a TIN bullet. Its always LEAD for expansion and NEVER “TIN” for expansion.
GOOGLE IS EVERYONES FRIEND YET NO ONE USES IT ❓
The Barnes varmint grenade and Speer TNT green have copper tin cores and have around awhile. Nosler makes a green pb slug to but I don’t know what the core is composed of.
[quote=”David.Soliman”]Don’t know about that but I have a tin solder that is 40/60 lead/tin and it is way too soft.
I’ll do a quick chemical test and check it out.[/quote
BS !!!!!!!dude you can’t find accurate equipment to determine the BHN of lead. The Redding/saeco has its own 1-10 scale, the lee goes by the size of the indention of your sample. The LBT BHN tester is long out of production and was the best. PELLETS ARE SWAGGED!!!! Swaging wire is pure lead . With the eception of crossman I think all pellets are pure lead. I really doubt jsb is using solder wire.Though the lead wire may have been harden by heat and quench, though this will cause the lead to be brittle and would affect how easy it is to swage. If any of you guys know about pellet swagging please speak up if im inncorrect about anything im a caster and just have a genral knowlegde of swagging. I would like to hear how you preform your chemical test, you may find lead tin and trace of bullshit 😥
Have you ever seen Lavenhook’s microscope, or Galileo’s telescope? You think how did anyone see anything with those pieces of junk? Early riflescopes are another example, and yet those guys put bullets on target at extreme distances. People have used these inferior techniques and apparatus to solve scientific questions. That’s how we got to the place where we could develop the mass spectrometer, electron microscope, Hubble Deep Space Telescope, and of course the Flux Capacitor! Really RC, where have you been? 🙄
Somebody wake up Uncle Hoot!
RC
And that is my point, unless you have a mass spectrometer it is a impossible task.
Thanks for a more eloquent description of the problems and improbability of getting it correct.
RC
RC, it is a viable way to determine the density of various non-combined or combined materials. Which I bet you knew. You are correct though, it has it’s problems when implemented by ammosmiths.
Once more than two materials are combined (to bring the total to three) there is no way to accurately determine the mixtures of the two small quantities of materials. Only their combined densities when combined with the major material density.
The Eureka test was used to determine if the gold was not 100% pure. Not what other materials were mixed into the gold. What else was mixed in there was of no consequence, the jeweler was toast if it wasn’t 100% gold. 😉
Say you have gold, silver and copper in a ball, but you don’t know you have copper, your estimate of the total silver content will not be correct. Or a tin/lead alloy bullet with a copper or steel core/jacket.
Some people use this method to approximate the weight of a gold vein in quartz. Problem is the specific density of quartz can vary and most people are looking for MORE gold than less. Often they over estimate the actual quantity of gold, hell it is in their best interest to do so.
The major problem is the amount of error involved in determining the volume of the object.
Depending on the graduated cylinder you use, just the meniscus can be 1/10th a milliliter or more and when the lead may be as pure 98%, the error in volume can completely skew the outcome.
I did plenty of this in chemistry lab in college with good equipment and we had to determine our quantity of error as various stages of the experiment. The error was in the volumetric measurements, the enclosed scales were good to 0.001 grains.
Some folks measure on what is effectively a mixing cup for paints with one fluid ounce graduations and estimate the distance between. If they were to run the numbers plus or minus five to eight percent they would be shocked at how different the numbers would be.
If you really wanted to get it right, it would be best to use a mass spectrometer. 😉
That would give you the percentage of each element in the alloy.
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Tof, thought google may have had a malfunction. There is a lot of odd materials that have been used for bullets. From naval bronze and depleted urrainium to bar stock nylon turned on lathe. Hell there were people in the 1800s that tried to cast mercury slugs. Thing is we always go back to pure lead. Jack carter used pure lead wire and pure copper jackets and bonded them like RC to make trophy bonded bear claws. The originals had a great track record until jack sold the rights to a major bullet maker and they changed the jackets to gliding metal which did not bond as well with pure lead.
😀 😀 😀
As a side note if any of you guys are casting wheel weights, be very careful as there is some environmental friendly additive now being used in their manufacture If the vapors are inhaled it will make you very sick.