Sorting pellets by viewing

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Hello.
The eccentricity of hollow or head are different for flat head and round head pellets. With round head pellets, the skirt can also be eccentric, but the head is heavier. Therefore, I rather check the head, but this is more difficult to assess. With AA and JSB pellets, the eccentricity can also be seen in the wobbling of the edge.

Currently, the adapter is a simple sleeve with a bolt. (This can certainly be made even better).

The sleeve is simply driven with a wooden rod. (similar to playing the violin).



Checking the head

IMGP4055.1629384116.gif




Checking the Hollow

IMGP4056.1629384733.gif




Let's see maybe I can make the testing machine simpler.


Maybe this software could also show the errors better.

https://www.youtube.com/watch?v=ozcKdCCK4U0



NoLimits




 
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This is very impressive stuff. I use a borescope focused on a pellet rotating on a turntable to assess the pellet quality and alignment. But this doesn't work well unless the lens and turntable are lined up perfectly and the pellet is placed perfectly at the center of the turntable. 

I agree that weighing, head sizing, yrrah rolling, and skirt/damage assessment do not fully distinguish good from bad pellets. My regression analysis of POI from highly stabilized benchrest shots says these variables explain only a small portion of the total variation. The other errors can be the gun, the shooter, wind, and unmeasured pellet characteristics.

I was unaware of this tool and will try to purchase it. If I can get one, I'll add it to the measurements of pellets for accuracy testing and statistical analysis. I hope it not only spots potential fliers but tightens up all groups.



Thanks for showing us this tool.


 
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Hello Strever,

that's a good question.

Normally, only flat-head pellets and some short round-head pellets are tested.

The length of these pellets still have a good relationship to the calibre dimension and the clamping sleeve.

Here are a few examples with flathead and roundhead pellets.



20210816143052.1629980850.gif


20210816143001.1629980865.gif


Flachkopf Diabolo exzentrizitt 1.1629981001.gif


Flachkopf Diabolo exzentrizitt 2.1629981030.gif


Or badly and well fitting heads with round head pellets.

202108201117041.1629981088.gif


202108201125211.1629981226.gif




Back to your question.
Somewhat longer pellets, such as JSB Monster, cannot be judged so well. You need some practice or experience. 

20210824095251.1629981682.gif


The cone and the head rotate well on the axis.
But the cylindrical part is slightly slanted and rotates eccentrically.

Flashing or pulsating lights are the first thing I look for.
Then I look at the contour.

JSB Monster.1629982345.jpg


NoLimits
 
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Hello BackStop,

I answer with some uncertainty. I have really done a lot of tests with symmetrical and unsymmetrical pellets. Fackt is, the unsymmetry (unbalance) can not be eliminated by different speeds.
An unbalanced pellet remains an unbalanced pellet. Just as an unbalanced car tire remains an unbalanced car tire.
However, one effect of the unbalanced pellet is similar to that of the unbalanced car tire.

Depending on the speed, the steering wheel wobbles more or less. 

There are certainly also interferences or harmonies between pellet speed, barrel vibrations. I have often experienced that some air rifles with +-10% speed had a better or worse accuracy. But this is normal. A small change in pellet weight has similar effects. 

Here you have to experiment a bit until the barrel and the bullet have the right (harmonic) amplitude at the muzzle.

But even then, a bad pellet remains a bad pellet and a good pellet remains a good pellet.

NoLimits
 
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Hello BackStop,

I answer with some uncertainty. I have really done a lot of tests with symmetrical and unsymmetrical pellets. Fackt is, the unsymmetry (unbalance) can not be eliminated by different speeds.
An unbalanced pellet remains an unbalanced pellet. Just as an unbalanced car tire remains an unbalanced car tire.
However, one effect of the unbalanced pellet is similar to that of the unbalanced car tire.

Depending on the speed, the steering wheel wobbles more or less. 

There are certainly also interferences or harmonies between pellet speed, barrel vibrations. I have often experienced that some air rifles with +-10% speed had a better or worse accuracy. But this is normal. A small change in pellet weight has similar effects. 

Here you have to experiment a bit until the barrel and the bullet have the right (harmonic) amplitude at the muzzle.

But even then, a bad pellet remains a bad pellet and a good pellet remains a good pellet.

NoLimits
Click to expand...


Thanks for the reply!
 
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Intriguing, Klaus-Dieter/ NoLimits! 😊

DANKE für deinen ganzen Aufwand uns diese Probleme so grafisch zu illustrieren! / THANK YOU for all your efforts to illustrated those problems for us to graphically! SUPER WORK! 👍

I'm very interested where this will lead -- I'm having hopes for improved precision in airgunning!

Matthias



PS: I'd be interested how H&N compare to JSB using your testing methods! Gotta love their slogan on the adhesive tape that seals every pellet tin: "German engineering – not just for cars." 👍
 
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Just curious, with the pellet holder aren’t you effectively sizing each pellet when loading? do you have specific ID holders say 4.51,4.52, 4.53 etc.

Do you use this device for sorting pellets to shoot in competitions? Do you find most all of the pellets in a tin (or whole lot) seem as consistent in the defects or is it totally random within the same tin?
 
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Hi there,

Please excuse my late news. I have a lot of work to do right now. I'm preparing for the German shooting championships (supported rest shooting).

Thanks for your interest. The test device (the test method) was developed mainly for Olympic disciplines for caliber .177 (flat head pellets). For some time now, more and more shooters with round head pellets (caliber .177 and .22) have shown interest in this test method.

Please be patient until I get back.

NoLimits
 
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"I agree that weighing, head sizing, yrrah rolling, and skirt/damage assessment do not fully distinguish good from bad pellets"

Agree. But does this rotational method "fully distinguish good from bad pellets"? It seems obvious that a pellet that "wobbles" would be "bad" so such a method should improve accuracy. But if one keeps only those that don't "wobble", would weight (or size or other) differences still be a relevant factor?
 
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NoLimits,

I would be VERY interested in getting one of these for .177. Through your demonstration, and videos, I'm sold. This could be one of the best methods for weeding out the bad pellets in a tin. Very interested in buying one of these machines. 

Tom Holland 

Field Target Tech 

Fieldtargettech.com
Click to expand...

Tom,

Go to https://www.lottessporttechnik.de

Look for the Joker-Measuring tool

I've tried it with about 50 pellets and did not get a significant correlation between the pellet characteristics in this tool vs distance from POA. But I will try it again next spring when I get back into benchrest shooting and search for ways to improve average precision and eliminate fliers.
 
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Months ago I was searching for a local lathe operator to make me some of these roll-testing sleeves for .22 and .25 (the OP built for .177 only) but nobody bothered to materialized. I am back to tinkering about a winter project. I am sitting on several dozen tins MRD's and not mad enough to go through a five-six steps of selection/sorting nightmare. I am even tinkering buying a mini lathe to support my hobby.
Anybody can confirm that this visual report is better maybe?

Edit:
Today I decided sourcing the pellet tube to a machinist, waiting for a quote. The main body I will 3d print.
 
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NoLimits said:
Hi there,

Please excuse my late news. I have a lot of work to do right now. I'm preparing for the German shooting championships (supported rest shooting).

Thanks for your interest. The test device (the test method) was developed mainly for Olympic disciplines for caliber .177 (flat head pellets). For some time now, more and more shooters with round head pellets (caliber .177 and .22) have shown interest in this test method.

Please be patient until I get back.

NoLimits
Click to expand...
Hi NoLimits,

Do you still sell this tool? I mean Joker .177
I tried several time to contact using contact form on https://www.lottessporttechnik.de/kontakt/
But no luck, no one replied. Any channel that I can use to contact you?

Thank you
Aldhy
 
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Stupid question if I may? The pellets/projectiles that are obviously not concentric what is the cause of this? Is the die, mold or machine out of spec? Does the quality or raw material used to produce a pellet have anything to do with concentrisity? Do manufacturers even use lot numbers any more or is lot numbers more of a pb thing? I’m not a competitive shooter but the example being shown are eye opening.
 
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Most of the issues you already pinpointed.
Machining the die two half's shall be identical, fine polishing the cavities and no misalignment when the tool is closed. The Temp during the swagging process and the press force to squeeze out any internal bubbles...and the die will wear out sooner or later after many thousands of cycles.
I am not a competitive shooter as well just a wannabe, but pretty much anal with my own rings scoring and always looking to blame on something else.
 
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