You guys will pellet scales ruined my day, thanks a lot!

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addertooth

addertooth

Member
Oct 3, 2016
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Arizona, United States
After watching all of the serious extreme bench rest shooters obsess over pellet weight and size, I broke down and bought a scale.
​The amount of variation (even with premium priced pellets) surprised me. Previously I made the grand assumption that the premium brands produced a product which was within one percent of each other (one part per hundred). It seemed reasonable, I mean, we are paying a premium price for great pellets. What I was not expecting was to find a 4.65% weight variation in a single can.
​I always thought some people were being silly weighing their pellets and putting them through a size gauge; it seemed to verge on an obsessive compulsive disorder. Now I am ruined. I am even wondering how much of the 1.88 percent velocity variation in my 42 shot string was my gun, or the pellet. Now I will probably end up being one of those pellet "tweakers" who buys a pellet diameter gauge.
​The picture is from the weight sorting results of JSB Exact King Heavy Mark II (33.95 grain) pellets from a single can. Weight ranged from 32.8 to 34.4 grains. 
610e48d4e8cf203da26fecfd9f3a4767.jpg
 
Much obliged! Welcome to the club LOL. This topic will most likely get moved to the pellet forum. That said, I also posted on this a month or two back. I shoot the JSB 25.39, I weigh and sort in 3 weights. I didn't go into as much detail as you have? But what I found was ........... 30 % 25.0-25.2 50-60 % 25.3 25.5 and the remainder over 26.0
My 26 plus tin is now full after 12 tins weighed so I'll weigh and sort them in .2 increments. I also wash but I don't lube,size or roll....yet.
I have noticed beyond 50 yards my groups really tighten up. 80-100 yard groups went from 4" plus to under 2" HUGE difference. The super shooters in EBR spend more time on this than I am willing to right now.
Lead on!
 
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On these pellet I will likely group 33.7 to 33.9 in one (prime) tin, 60 pellets. 34.0 to 34.2 in another "heavy" tin, 29 pellets, and 33.4 to 33.6 in a third "light" tin, 43 pellets. The rest will get tossed in a tin labelled "plinkers". Out of this group, it would be 21 plinkers, out of a tin of 150.
I will have to look at your posting 2D1C, I looked for, but missed the Pellet Forum.
 
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you are not very good at interpreting statistical data.

looking at your data, i would say you have some issue with your digital balances, your data set should be more look like a gaussian distribution. i guess if you reshuffled the pellets and measured them again, it would spread more evenly. anyway.


you have to understand JSBs are made to high 5%specs.

Look at it this way there are 0 pieces of 1 grain, 0 pieces of 2grain pellets... up to 32.8grain, then after your group finishes there is no 35grain or 36grain etc. so basically a discrete 'distribution'.

some speculate that heavy pellets have better BC anyway so they don't drop off that quickly if this makes sense to you.

if you want to go really anal I would suggest to get rid of those scales and get proper laboratory balances with closed compartment, then you can take this to a higher level of madness.
i have seen a better sorted set, and the person who did it managed to sort .177 pellets which are a lot more difficult to handle and make.
the specs are 5% and your set is better than that. who cares if it averages around 33.7?
 
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That spread seems about par for the course for JSB these days, regardless of caliber. I have some tins of Air Arms(made in same factory) and JSB 10.34gr in .177 from three years ago and while the AA's have a tighter spread in weight, the JSB's look like your spread. I've had similar results with JSB 8.4gr as well in the past.
 
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they sell machine sorted weight specified pellets in the small caliber. if you want to pay the price, not sure if it is worth it.
the wind will mess with the POI more than the weight... 
you want to shoot the gun more, i would change a barrel if your gun does not group well instead of the womens do. men are not very good at this tedious task.
very boring, zero fun.
 
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Sirk, 
I had similar concerns that something was strange, so earlier (before posting) I re-weighed a sampling pellets out of each group to confirm the scale was accurate. It is accurate and repeatable. The scale had also been checked against a lab standard NIST traceable weight as well. I had expected a bell curve as well, centered on 33.95 grain, but you can't ever argue with data (assuming it is accurate).
​Since this initial group, I have sorted a few more tins. Each tin acts generally in the same way, with one tin favoring lighter weights. Keep in mind I have 23 tins of this pellet, so I should be able to separate them into some nice tins of plus and minus 1/10th of a grain from a central value. This should be close enough. And yes, I caved in and ordered a 25 caliber pellet gauge after my posting; I also already have the ingredients for whiscombe's Honey.
Anything worth doing, is worth over-doing ;) 
 
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I sorted a couple tins of JSB 22 cal 18.3s a few months back. The results scared me. I don't sort anymore. I just shoot them as they come out of tin. I figure I am not good enough for blaming any fliers on a few tenths of a grain difference in pellet weight. I find I have more problems with the bent skirts. Like has been said, these pellet are not cheap by any standard (JSB MKIIs Being about 10 cents each) you would expect better quality control.
 
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What would be interesting to know is if there is always a direct corollation between a single tin and a single die. Or are we getting a blend of dies (which I suspect). Also how diligent do JSB monitor the wear on their pellet dies and the quality of lead they receive from suppliers, compared to the level of QA that they put into FX or AirArms branded pellets. FX and to some extent AirArms, have higher spec’d guns, so it is in their interests to ensure their version of JSB pellets are of a higher, consistent quality, or is it just another “marketing gimmick” to promote their brand? It would be really helpful if we could get some feedback from the manufacturers on this.
 
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I went to the range today to see what if any POI there was between the 25.0 -25.2 and the 25.3-25.5's, it was closed so set up in the another place I shoot from.
Lousy rest (TV tray) and wind in excess of 15mph 50yards distance. To windy to be conclusive. Was great to get out and shoot having finally repaired the AW!
Next order I place I am going to try a tin of the AA and or FX to compare. This topic is coming up more and more.
 
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before we obsess with weight, remember the object is accuracy. what I suggest is that shooting pellets of the same weight (or nearly) will give uniform (????) results.
​conversely the sorted pellets , if organized by similar weights can be shot with accurate results if all your pellets are of the same weight (or so)!
​so by using your 25.8 "culls" you can shoot them as accurately as the 25.4's. its just so your shots group accurately and you can hit your target.
make sense???
 
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There are 3 common pellet sorting areas where people obsess. Pellet Weight, Head diameter, head to skirt ratio (roll test). Of the three, most people who have posted groupings, seem to show the greatest gains in repeatability is via head size. Assuming the head size is uniform, then weight differences "can" come in from minor changes in overall length and thickness of the pellet's skirt. I broke my pellet sorting into 5 groups. With the central group being 33.7 to 33.9. It was the most plentiful group (out of a thousand pellets eventually sorted). The last major groups were the "light group" at 33.4 to 33.6 and the "heavy group" 34.0 to 34.2 .. The last 2 of the 5 groups were the pellets under 33.4 (with several as light as 32.7 grains) and the over 34.2 (with a few 34.5 grain samples) group. I refer to these last two groups as my culls. The last two groups had a greater variability than the 3 main groups which were plus and minus 0.1 grain from a central value.
​The pellet gauge should arrive sometime this week. So I will go through the cull groups and see if the headsize has more variability in the more extreme groups, than the 3 main groups which have more a consistent weight. If we start with the assumption that the lead alloy has a relatively consistent density, any change in weight can only mean a change in dimensions (or for light pellets, voids in the casting/forming). With all of these potential different weights and head size, I am beginning to wish I had not thrown away some of my empty tins in the past.
 
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