Pellet weighing...

S

ShadowChaser

Guest
Ok, Folks, tell me about pellet weighing, I assume its an important part of achieving the type of accuracy AGBR shooting requires.

What's a good scale to use? How accurate does the scale need to be?

What is a match grade pellet, and where do you purchase such match grade premium pellets?

Thanks for your help,
Mitch & Shadow...
 
Weighing these little buggers is going to be a pita as they are around 7-10 gr. for .177 and 12-20 or so for .22. the upscale pellets with today's mfg. processes, I will guess, vary less than 1% Any of the high quality scales would work. Pilkingtons, Champions Choice, Champion Shooters Supply, + others carry the match quality pellets. As with rim fire each gun has its favorites. Far more important than the smidgen of weight variation, is the dia. .177 match pellets range from 4.48 to 4.51, uniformity of the skirt is the single most important aspect. Washing the pellets in break cleaner or something like it( no residue left behind) to rid them of any chaff left behind during mfg. is also important ( in the bulk tins). There are pellets available that are individually packaged. Lubrication of the pellets is questionable as to accuracy enhancement. As the primary component is lead and the velocities seldom exceed 950fps it is not really needed. Note that today's pellets are an alloy, primarily to prevent oxidation. Another tidbit is diablow style pellets in .177 at apx 8gr achieve their best stability at apx 525-600 fps (from my 10 meter days) From the Field Target guys the round headed pellets are somewhat more accurate at ranges greater than 10 meters but they are mostly using velocities in excess of 700fps in .177.
 
More on Pellet Weighing...

I think its time to bump this subject back to the top...

The subject of this thread is "Pellet weighing"...

I'd like to expand the thread subject to read "Benefits of Pellet weighing for competition shooting"

Now that I have a couple of PCP guns that are showing great promise, I find myself being frustrated by having a good target going and suddenly have a shot unexplainably show up in the 9 or 8 ring while the gun stays positioned in the rest with the scope crosshairs still centered on the 10 ring in the center of the target. This often happens after shooting 8 or 10 or 12 clean 10X shots in a row and on several occasions, I have made it to bullseye #25, and carefully squeeze of the last shot needed to finish and have it be a flier.

So, I have been on a quest to try and figure out what causes this to happen when I'm positive that it is not me or my gun causing the problem. There are times when I get careless and screw up for lack of a better way of putting it, but I know when those times are and I can account for errant shots that I produce by my own fault. I also know by the sound of the gun firing and how the gun reacts and recoils when something is amiss with the way the gun functions. However after hundreds of targets and thousands of shots with the two guns I am presently shooting, there is a small number of random shots that differ from the POA when all is right without any explanation and I've become convinced this is a pellet anomally of some sort.

This has lead me to spending a lot of time recently inspecting pellets, first visually, then rolling them on a flat surface to see how smoothly they roll or wobble as the case may be, and finally I have come back to my original question of pellet weight and its effect.

I have a number of scales, both digital and analog, and quickly came to the conclusion that having a resolution of 1/10 grain, while allowed me to see some variation in a 10.5 grain pellet, mainly that there is a variation of a couple tenths of a grain from the manufacturers stated weight, and that pellets, even match grade, do vary a couple tenths one way or the other through a tin. I started grouping them as best I could by weight and this did seem to have me headed in the right direction. I was reducing the number of unexplained fliers by weight sorting the pellets as best I could using what I had to work with.

At this point I was quite certain that what I was finding as pellet weight extremes from one end of the weight range to the other in a given tin was what was causing the fliers. If a pellet of lowest weight or highest weight is randomly mixed in with a group of pellets of the nominal weight range which seems to be the majority in a tin, and you are adjusting your point of aim slightly to allow for small variations and suddenly get a pellet of weight at the other end of the range of those you are presently shooting, the end result is a shift in POI that you are not expecting...

Therefore, encouraged by what I'm seeing of weight variations as a potential cause of the unaccountable fliers, I spent several days researching scales to see what was available that would have better resolution for what I was attempting to accomplish. The end result of my research led me to purchasing an "Acculab" VIC-123 digital milligram scale that has a number of features and programming functions that gives me resolution of 0.02 grain, has a fast response time, and would be easy to use without costing an arm and a leg.

http://www.affordablescales.com/scales_specs.asp?specs=558


Several days ago my new Acculab VIC-123 scale arrived, and its no disappointment! Very nicely made, easy to set up, and in minutes, I was weighing pellets. Even for being very cold as it has been in unheated UPS trucks for three days getting to me, this scale is showing me what I wanted to see right off...

First thing I did was to weigh a couple dozen pellets simply to see what the range of weights is, the pellets I used to start my refined experiment are Crosman Premier Heavy 10.5gn per the manufacturer. Only reason for choosing this pellet is I had an open box sitting on my bench that I had been testing and shooting with good luck and they were the first in reach once I had the scale setup.

What I found by weighing several dozen of these 10.5 gn pellets was that the weight ranged from 10.4gn to 10.84gn as I selected them at random from the box they came in. This is a total weight variation of 3% and I was quite surprised to find it to be what I consider extreme. What needs to be done to correlate this to POA/POI variations is to measure changes in velocity cause by weight and calculate and graph the effects on external ballistics however I do not have a chronograph so have to act on the assumption that a 3% variation in weight has to have some effect although I do not know exactly what it is at present. I can only assume there is an effect that is present based on my knowledge acquired of years of working with precision shooting and ballistics. Someday, I'll have to add a chronograph to my collection of tools but for the moment am satisfied that an effect of the 3% weight variation must exist.

At this point, after letting the scale come up to room temperature and stabilize, I decided the next step in looking for cause and effect,was to set up a number of pellet tin lids with labels, 10.40, 10.45, 10.50, 10.55, 10.60, 10,65, 10.70, 10.75 and I started weighing pellets.

Here is a tip for anyone attempting this, I quickly learned to place a disc of the foam that comes in JSB pellet tins on the scale stainless platform and use a pair of large tweezers to pick up an place pellets on the foam pad. If you zero the scale with the foam pad in place, the scale displays the tare weight of the pellet and not the pad and the pad keeps the pellets from rolling all over the small stainless platform as you try to pick them up.

Once I had pellets in groups as labeled plus or minus .02gn, the largest group was the 10.6gn and I proceeded to set up a gun on my test range and shot a clean target with no fliers!!!

In the past two days, I have repeated this process a number of times with the .177 gun and then switched to the .22 cal gun and a tin of JSB Exact Jumbo Heavy 18.0gn pellets. What I found as I started weighing the pellets was a repeat situation I had found with the .177 pellets and that was a variation in weight ranging from 17.90 to 18.84 with one or two outside that range of extremes. Again it is a 3% weight variation found in one tin of pellets.

Again I weighed pellets into groups of .05gn difference, and found the largest groups to be 18.15gn and 18.2gn and I proceeded to shoot a couple targets with these weight sorted pellets and again had two clean targets with no fliers...

Over a couple of days of testing, I have come to the conclusion (probably prematurely as I'm just getting started) that weight sorting does work when you are looking for that one or two point edge required to win a benchrest match... I say this may be a premature conclusion as I've only been at this a week and have not tried weight sorted pellets in a match yet and I'm still way down on the learning curve about precision PCP airgun shooting...
In any case I'm pleased with how this experiment is going, I think I've found the result and explanation I was looking for and want to lay it on the table for discussion...

Ok, Y'all, Comments and suggestions, please...

Happy Shooting, Y'all...

Mitch & Shadow...
 
Last edited by a moderator:
Strange as it may be

blades said:
Weighing these little buggers is going to be a pita as they are around 7-10 gr. for .177 and 12-20 or so for .22. the upscale pellets with today's mfg. processes, I will guess, vary less than 1% Any of the high quality scales would work. Pilkingtons, Champions Choice, Champion Shooters Supply, + others carry the match quality pellets. As with rim fire each gun has its favorites. Far more important than the smidgen of weight variation, is the dia. .177 match pellets range from 4.48 to 4.51, uniformity of the skirt is the single most important aspect. Washing the pellets in break cleaner or something like it( no residue left behind) to rid them of any chaff left behind during mfg. is also important ( in the bulk tins). There are pellets available that are individually packaged. Lubrication of the pellets is questionable as to accuracy enhancement. As the primary component is lead and the velocities seldom exceed 950fps it is not really needed. Note that today's pellets are an alloy, primarily to prevent oxidation. Another tidbit is diablow style pellets in .177 at apx 8gr achieve their best stability at apx 525-600 fps (from my 10 meter days) From the Field Target guys the round headed pellets are somewhat more accurate at ranges greater than 10 meters but they are mostly using velocities in excess of 700fps in .177.
Click to expand...
------------------------------------------


I have come to different conclusions to the above comments, on several points:

While I have found the skirt diameter to be near impossible at accurately determine (bent ones may measure smaller or larger, depending, yet in reality, be the same as the rest) , I have found it to be much LESS important than head diameter, and both of these attributes to be somewhat less important than weight variations as are commonly found even in "best quality" pellets. Furthermore, I have seen a great benefit to lubing pellets, and have been doing so with good results for decades.

The scale I have been using lately with good results is a gemscale from AWS called "dia-10". It weighs down to the milligram, which is well under a tenth of a grain. Practically speaking, I find sorting pellets to the nearest tenth og a grain is enough to give significantly few fliers under iideal conditions, and the difference is even MORe noticed in bad conditions!
 
Go No Go

In Field Target many shooters use a Gauge of some sort to drop the pellets into to make sure they are uniform in diameter. In guns that have the pellet fed directly into the bore a relatively loose pellet can be detected rather easily. Guns which have a bolt that seats the pellet into the rifling are harder to detect loose pellets.
I've ruined enuf good groups when testing US FT's in LD's tunnel to make sure I don't trust the loose ones to fall into the same group as the rest regardless of weight.
I also weigh pellets to the nearest tenth and group by 10.45-10.55, 10.55-10.65 and then the rest I just use to condition the barrel when running in a fresh bore.
LD discovered the KryTech Lube benefits and we have used the lube on all the Crosmans we shoot. JSB's don't seem to need lube. Barrel cleaning becomes childsplay and frequency if extended so lubed pellets are one of the things we do besides weighing the ammo.
 
Tim McMurray said:
In Field Target many shooters use a Gauge of some sort to drop the pellets into to make sure they are uniform in diameter. In guns that have the pellet fed directly into the bore a relatively loose pellet can be detected rather easily. Guns which have a bolt that seats the pellet into the rifling are harder to detect loose pellets.
I've ruined enuf good groups when testing US FT's in LD's tunnel to make sure I don't trust the loose ones to fall into the same group as the rest regardless of weight.
Click to expand...

Tim, please describe the gauge you are talking about. I've heard of others gauging the diameter of pellets but have no understanding of just how this is accomplished or what the gauge is. Can you provide more detail please about gauging pellet diameters?... For a newcomer, just how some of this is accomplished is a bit of a mystery to me...

Thanks...
Mitch & Shadow...
 
please reweigh your pellets on

2 more occasions,

say your pellet weighs 10.4 does it weigh 10.4 a week later or 2 weeks later, what i mean by this is the scale can wander from week to week casu9ing different measurements

the lapua brass is separated on one day into lots

not on 4 days into lots
Jeff
 
Roll them..............!

There is a fellow from Oz named Harry (Yarrh) who believes rolling pellets as a way to sort them is a benefit. Seems to make since as LD said diameter is important. If they roll to the same spot there a real good chance they would be the same dia. head and skirt. So, weight them, run them through a die, roll them and lube them and all bases will be covered. :rolleyes:

D R
 
Jefferson said:
2 more occasions,

say your pellet weighs 10.4 does it weigh 10.4 a week later or 2 weeks later, what i mean by this is the scale can wander from week to week casu9ing different measurements

the lapua brass is separated on one day into lots

not on 4 days into lots
Jeff
Click to expand...

Jeff, Thanks for your interest and comment... Yes, scales do vary with time, there is no doubt of that however pellets do not and that is what is important here as I see it.

The purpose of weighing pellets is to weight sort them into groups of 1/10th grain variations. I can weight sort a tin of 500 pellets in less than two hours and once I have stored the pellets by their weight group, what they weigh after that is accomplished is no longer important as I see it. So there is no point or need to weigh them a week or two later as you suggest.

I guess the thread title would be more apt if I'd used "Pellet weight sorting" instead of "Pellet weighing"...

Besides, I rarely have the same pellets on hand for longer than a week or two, I go through 1/4 to 1/2 tin a day in the evaluation and development of the two guns I am working with and am constantly waiting on the UPS truck to bring me more it seems... Its called being retired and having one's own indoor range, what better way to spend a new England winter than building a couple of benchrest guns and finding the pellets that shoot best in them...

Happy Shooting...

Mitch & Shadow...
 
Last edited by a moderator:
D R Greysun said:
There is a fellow from Oz named Harry (Yarrh) who believes rolling pellets as a way to sort them is a benefit. Seems to make since as LD said diameter is important. If they roll to the same spot there a real good chance they would be the same dia. head and skirt. So, weight them, run them through a die, roll them and lube them and all bases will be covered. :rolleyes:

D R
Click to expand...

D R, Now you've touched on an interesting subject... I've heard of Harry Yarrh, never been in contact with the fellow, but from what I have heard, seems like he's provided a lot of good information to the airgun shooting community...

When you talk about rolling pellets, I assume you mean simply to roll them down a flat surface and see which ones track true and which ones wobble about. I ask as I do this, one can learn a lot about how a pellet rolls however recently I've learned about a fellow by name of John Sills or Stiles (I'm not sure of his last name at the moment), some years back, this fellow designed a set of dies made of flat steel plates with a pellet profile machined into one edge of each and the idea is that with these mounted on a plate spaced at a precise distance apart, this space being adjustable with shims and one of these dies being fixed and the other sliding past it, a pellet would be rolled between them reshaping, resizing, and truing the pellet.

I have some poor pictures of one of these pellet truing devices and have given it some thought however at this point am not sure its worth the cost of having one made...

First, the pellets today are made to much higher standards and tolerances than they were ten or fifteen years ago. With pellets costing about 2 cents apiece presently, as long as we can sort out the few in a tin with obvious defects, a lot of which shows up in weight sorting and a visual inspection as one handles each pellet one by one to place them on the scale, the obvious defects become apparent and those pellets get dropped in the scrap. The cost is only a few cents and hardly makes spending hundreds of dollars for a special tool practical...

I find the amount of malformed pellets to be only a very few in a tin of modern pellets, something like two to six worst case so the hundreds of dollars of cost to have a Tool & Die shop make such a pellet truing set of dies today is very hard to justify.

And then there is the factor that each company manufacturing pellets today uses a different profile. At present I am using Beeman Kodiak, JSB Exact Diablo Heavy and Crosman Premier Heavy and each would require a different set of dies as I see it.

I've wondered if a set of dies that only shapes the outer end of the skirt and the rim of the head would help but it would do little to alter the runout of the mass of the pellet. Would sizing the rim of the head and the edge of the skirt be enough?

At this point, I'm seeing weight sorting and discarding obviously deformed pellets is eliminating all the few random severe fliers that I was getting at the start of this project and my testing has shown that lubing does improve accuracy.

My one issue to overcome at the moment is how to size pellets. I've tried calipers and micrometers and come to the conclusion they do more harm than good as well as being cumbersome. So, my big interest at the moment is to find a gauge or die I've hear others talk about, something I believe consists of a hole that pellets get dropped or pushed threw, however I have never seen such a gauge or have any idea of what to look for in a gauge...

Any light you can shed on this subject is more than welcome...

Thanks for your interest and help...

Happy Shooting...

Mitch & Shadow...
 
Gauge

As I mentioned in the earlier post I sort undersize by how they feel going into the bore as my rifles get fed directly and it is pretty obvious when a pellet is undersize.
Undersize seem to be mostly eliminated with the weighing but not entirely, so I suspect underweights and undersize go hand in hand to a high degree.
Gauges can be a clear pen body as they always have a bit of draft if you can find one the right size. Mark the outside of the pen body with the acceptable range or typical stop point and anything that drops in less or more is a reject.
You could get elaborate and make one with a tapered reamer but I think with a little work you can find an injected part with the appropriate hole size and draft. Things injection molded are generally slightly tapered to allow the release of the part from the tooling.
This is a process guys with bolt action guns that can't feel the pellet entering the lead should consider doing.

Later

Tim
 
Pellet Size Die

Beeman use to offer pellet sizing dies many years ago. They were just a short piece of anodized aluminum tube that you pushed the pellet through with a little punch. One end of the punch had a ball on it to iron out dents in the skirts before pushing them through the sizing tube. I had one at one time but never really used it as accuracy out of my FWB 124 was plenty good enough for pest popping right from the tin. I may have to try and find it and give it a serious test with a bench gun some day.

Dennis
 
Krytech

Which type of Krytech are you using? There appears to be a couple of different types. Thanks.
 
Mitch, if you're interested in pellet sizers give me a shout and I'll put you onto a guy in the UK who will make them for you, he's quite happy to ship kit to the US and his prices are very good.
I size all my pellets and extensive testing has proved to me that this helps improve my group sizes.
As usual, if you need further info just shout.

Robb H
 
sizing pellets

all this is very good advice . you have to weed out the bad ones 1st weighing them is the best and easest form of doing that and gives you a chance to see if there is a defected one in the batch. lube is another thing that i think is good -at 950-1000 fps.and last you have to know how fast its going ! so sort all these pellets out and take your crony out to the range set up your bench and have fun,you will be amazed to see what happens. and at the next match you just might come in 1st.good luck. deleterman.
 
Finishline KryTech Wax Lubricant

It comes in a 4oz dripper bottle and is a bicycle chain wax.
Originally it was available in an aerosol sprayer (11oz) but that is no longer available.
The formulation uses Dupont Krytox which is an effective way of bonding the wax to metal surfaces. It is claimed that it sheds grime which could be the reason barrel cleaning intervals are invariably increased in duration.
The coolest thing for me is the cleaning of KryTech treated barrels tends to be a 3-4 patch affair. The first patch gets most everything in the barrel cleaned out so it is pretty gross but by the fifth patch you are already overcleaning.
The stuff dries completely and only leaves a waxy surface on the pellets. You could dump your pellets in fine dirt and the dirt would blow off rather than turn into a muddy mess like most lubes would create.
It also can be used in all your airguns regardless of type which some lubes can't because they make springers deisel.
The carrier is Butyl Acetate and evaporates rapidly after application. This is the stuff the fire breathers use to blow flames so it is very mild but highly conbustible.
Best approach to application is to put a half dozen drops on the inside of a half full (250 pellets)tin lid and roll the tin until the lube is evenly distributed. Leave the tin open until the carrier is evaporated.
A four ounce dripper bottle will probably treat 30-40 thousnd pellets so it is important to not overdo it. The bottle is clear so you can see the wax settle to the bottom occupying maybe 1/6th of the bottles volume. It is real important to shake the bottle vigrously prior to use as you want the goo on the bottom suspended in the carrier for best effect.
I sell the stuff along with the Crownsaver patch puller and a bag of patches for $15.50 or the wax alone for $5.50/4oz.
You want to start with a clean barrel for best effect as otherwise it is like waxing a dirty car.
You can get it at most quality bike shops or mac1airgun@gmail.com
 
weighing pellets

Tim, boy that sounds like good stuff from the gods. do all the top shooter use this stuff? again thanks for your helpful info.deleterman.:)
 
ShadowChaser said:
D R, Now you've touched on an interesting subject... I've heard of Harry Yarrh, never been in contact with the fellow, but from what I have heard, seems like he's provided a lot of good information to the airgun shooting community...

When you talk about rolling pellets, I assume you mean simply to roll them down a flat surface and see which ones track true and which ones wobble about. I ask as I do this, one can learn a lot about how a pellet rolls however recently I've learned about a fellow by name of John Sills or Stiles (I'm not sure of his last name at the moment), some years back, this fellow designed a set of dies made of flat steel plates with a pellet profile machined into one edge of each and the idea is that with these mounted on a plate spaced at a precise distance apart, this space being adjustable with shims and one of these dies being fixed and the other sliding past it, a pellet would be rolled between them reshaping, resizing, and truing the pellet.

I have some poor pictures of one of these pellet truing devices and have given it some thought however at this point am not sure its worth the cost of having one made...

First, the pellets today are made to much higher standards and tolerances than they were ten or fifteen years ago. With pellets costing about 2 cents apiece presently, as long as we can sort out the few in a tin with obvious defects, a lot of which shows up in weight sorting and a visual inspection as one handles each pellet one by one to place them on the scale, the obvious defects become apparent and those pellets get dropped in the scrap. The cost is only a few cents and hardly makes spending hundreds of dollars for a special tool practical...

I find the amount of malformed pellets to be only a very few in a tin of modern pellets, something like two to six worst case so the hundreds of dollars of cost to have a Tool & Die shop make such a pellet truing set of dies today is very hard to justify.

And then there is the factor that each company manufacturing pellets today uses a different profile. At present I am using Beeman Kodiak, JSB Exact Diablo Heavy and Crosman Premier Heavy and each would require a different set of dies as I see it.

I've wondered if a set of dies that only shapes the outer end of the skirt and the rim of the head would help but it would do little to alter the runout of the mass of the pellet. Would sizing the rim of the head and the edge of the skirt be enough?

At this point, I'm seeing weight sorting and discarding obviously deformed pellets is eliminating all the few random severe fliers that I was getting at the start of this project and my testing has shown that lubing does improve accuracy.

My one issue to overcome at the moment is how to size pellets. I've tried calipers and micrometers and come to the conclusion they do more harm than good as well as being cumbersome. So, my big interest at the moment is to find a gauge or die I've hear others talk about, something I believe consists of a hole that pellets get dropped or pushed threw, however I have never seen such a gauge or have any idea of what to look for in a gauge...

Any light you can shed on this subject is more than welcome...

Thanks for your interest and help...

Happy Shooting...

Mitch & Shadow...
Click to expand...

FYI Mitch,

http://home.hiwaay.net/~ispellan/PelletTest01.html

D R
 
weighing pellets

sizing pellts is a waste of time !! it was a scam back in the 80"s alot of different sizes was on the market.people caught on to that a long time ago. don't waste your $ . thats my advice. does anyone have a better answer?? happy shooting. deleterman.
 
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