how far down the rabbit hole with pellet weights.

The pellet manufacturers tend to think that .10gr is meaningless.

rangur1,

If your measurements are in grams, not grains, in my opinion, that is a lot. If you have a grain setting on the scale, that would be a finer scale to use.

When I sort my 8.44 grain pellets, or similar weights, I'll use everything from 8.42-8.46 grains. In your case of using a much heavier weight, it's less critical the heavier you go. For your purposes, I would say everything from 33.95-34.05, would be in the acceptable range for accuracy.

Tom Holland 

Field Target Tech 

A fellow with access to a 7th decimal chemical scale weighed 500 pellets. Only 2 were dead on 18.13

I guess it depends on if you’re into competition or not. I’m not & my OCD is limited to cleaning.

Friend,

I think you have done the most important thing in sorting bent skirts and head diameter. Tom is spot on. I would take a group of pellets with know weight differences varying .1 and see how they group. I would then compare that to a group shot with pellets varying .05. If the groups are about the same and meet your minimum needs, go with the larger variation. You may even want to expand the weight difference until the shot group spreads. That way you know what works with your weapon. Some will tolerate a wider weight variance than others, just as they shoot pellet brands differently. Perfect is the Enemy of Good Enough. LOL

Charlie

Friend,

I think you have done the most important thing in sorting bent skirts and head diameter. Tom is spot on. I would take a group of pellets with know weight differences varying .1 and see how they group. I would then compare that to a group shot with pellets varying .05. If the groups are about the same and meet your minimum needs, go with the larger variation. You may even want to expand the weight difference until the shot group spreads. That way you know what works with your weapon. Some will tolerate a wider weight variance than others, just as they shoot pellet brands differently. Perfect is the Enemy of Good Enough. LOL

Charlie

Click to expand...

The above is a good recommendation but depending on your shooting needs, POI might be just as or more important than group size. As much work as you've already put in to it, I would take heaviest, average, and lightest pellets of the different head size groups and check them for grouping and POI. Then check against unsorted to see if the sorting is gaining you usable performance. Results would be interesting to see.

I weighed a few thousand 7.9 grain Crosman CPLs and the total weight spread was .36 grains with most falling into a .24 grain spread..........

 



I also weighed up a bunch of .177 8.44 grain JSB Exacts and had a bit larger weight spread of .44 grains ...........





I do find weighing pellets rather tedious (more tedious than measuring pellet heads) and for my shooting weighing is pretty much a waste of time.

Opinions vary.

rangur1,

To have an extreme weight spread of 1.7 grains for a pellet of that weight, in my eyes, would be too much. Just the difference in weight alone, IF everything else (head size skirt size) is consistently the same, will vary greatly. As I noted before, it's not as critical for a heavier pellet, but in my experience, even small variations in pellet weight can make a large velocity difference.

If you check out my pellet sorting techniques on my channel, Field Target Tech, I describe in detail how I've found that all of the pellets flaws combined, (weight, head size, skirt size) make for a pellet that varies greatly in FPS muzzle velocity.

Here is the video which I describe the differences that weight/head size create. Keep in mind this is with an 8.4 grain JSB.

https://youtu.be/BDA5exy2jKM

Tom Holland 

Field Target Tech 

rangur1,

To have an extreme weight spread of 1.7 grains for a pellet of that weight, in my eyes, would be too much. Just the difference in weight alone, IF everything else (head size skirt size) is consistently the same, will vary greatly. As I noted before, it's not as critical for a heavier pellet, but in my experience, even small variations in pellet weight can make a large velocity difference.

If you check out my pellet sorting techniques on my channel, Field Target Tech, I describe in detail how I've found that all of the pellets flaws combined, (weight, head size, skirt size) make for a pellet that varies greatly in FPS muzzle velocity.

Here is the video which I describe the differences that weight/head size create. Keep in mind this is with an 8.4 grain JSB.



https://youtu.be/BDA5exy2jKM



Tom Holland 

Field Target Tech

Click to expand...

Excellent. Nicely explained.

rangur1 said: the range is about 5% of pellets total weight / mass. 

My experience wieghing them showed most in t he middle of the bell curve. Weiging brown box CP's, I'll shoot for record the 7.8 --8.0

stuff outside that was relegated to testing or chrony work, and stuff wayyy outside either end got trashed.

decide where those boundries are, itll be easy after that

Easy? Don't think so. Head size AND weight, as Tom Holland explained above, is what I've always thought to be ultimately relevant. Can sorting for any one parameter improve performance? Seems it probably would. Worthwhile? Seems it would depend entirely on the individual and the shooting needs at hand.

7.8-8.0 grain, interesting choice of weights because the lot I chose to shoot were 8-0 -8.6 grain. Out of the 3 remaining boxes of die "B" CPLs I found that most of the pellets from the "7.9 grain boxes" weighed more than 7.9 grains...........



Still, as long as the pellet heads fit snugly I could determine no difference in accuracy regardless of weight after removing the few under 7.90 grains and above 8.12 grains (1/4ish total variation)........





As a side note, I'm down to my last full box of die "B" CPLs from the 4 case purchase back in June of 2015 so I ordered a few tins of 4.52mm 8.4 grain Air Arms Domes for testing before placing another order for CPLs. I tested the AA domes and they were actually pretty good shooting from my .177 HW95, however they weren't better than the die "B" CPLs I've been shooting so yesterday I ordered another case of 1250 count, 7.9 grain .177 boxed CPLs. LOL.....I wonder what die lot I'll be getting since the 2015 order and how the new order compares to the old order.

I'm of the opinion that even pellet head size matters little as long as the smallest head is reduced when pressed into the leade. My experience has been that the fliers happen when a pellet head is too small to be "swaged to leade size" when loading. 

Years ago (around die #7) Crosman had QC issues with their boxed CPLs and there were quite a few "pee-wees" in every box. I learned that shooting a "loose fitter" compared to a normal "snug fitter" would be a flier. What I did back then was to simply drop a CPL into my R9 leade and if it visually sat in the leade at the proper height it was "pressed home" and shot. If the CPL sat too low after dropping into the leade (due to a small pellet head), it was removed and replaced with a good fitter.

A while back I tried a few tins of supposedly 4.52mm JSB Exacts and ALL were loose fitters in the R9 leade with a lot of "really loose fitters" and I would get a lot of "called fliers" determined simply by the fit in the leade. Matterr of fact, at one field target match I had two dry fires with my R9 and would have had a third if I didn't see the Exact flip out of the leade when re-latching the barrel.

Anywhoo.......if there is a mix of loose fitters and not so loose fitters in a tin of pellets, sorting of pellets by head size to weed out the undersized pellet heads will be useful.

LOL....die lot marked and dated 7.9 grain Crosman Premiers have relatively large pellet heads (mine ranged from 4.53mm-4.55mm) with loose fitters few and far between........

I'm of the opinion that even pellet head size matters little as long as the smallest head is reduced when pressed into the leade. My experience has been that the fliers happen when a pellet head is too small to be "swaged to leade size" when loading. 

Years ago (around die #7) Crosman had QC issues with their boxed CPLs and there were quite a few "pee-wees" in every box. I learned that shooting a "loose fitter" compared to a normal "snug fitter" would be a flier. What I did back then was to simply drop a CPL into my R9 leade and if it visually sat in the leade at the proper height it was "pressed home" and shot. If the CPL sat too low after dropping into the leade (due to a small pellet head), it was removed and replaced with a good fitter.

A while back I tried a few tins of supposedly 4.52mm JSB Exacts and ALL were loose fitters in the R9 leade with a lot of "really loose fitters" and I would get a lot of "called fliers" determined simply by the fit in the leade. Matterr of fact, at one field target match I had two dry fires with my R9 and would have had a third if I didn't see the Exact flip out of the leade when re-latching the barrel.

Anywhoo.......if there is a mix of loose fitters and not so loose fitters in a tin of pellets, sorting of pellets by head size to weed out the undersized pellet heads will be useful.

LOL....die lot marked and dated 7.9 grain Crosman Premiers have relatively large pellet heads (mine ranged from 4.53mm-4.55mm) with loose fitters few and far between........

Click to expand...

Possible but I agree with Tom Hollands view on possible changing of resistance with head size variance.

"possible changing of resistance with head size variance".

Hummm....how can there be "changing resistance with head size variance" IF the pellet heads are large enough to be swaged down to size when pushed into the leade the "head size" will be consistent when shot.

CPLs at shot from .177 HW95 or .177 Beeman R9 break barrels when sitting on a bucket resting the gun on cross sticks.........









Notice the tight fitting CPL group in the upper left hand corner of the target from the "looser leade" .177 Beeman R9 vs the looser fitting 7.33 & 8.4 grain AA domes shot from my R9...........



Sorting my CPLs by weight and/or head size doesn't help my accuracy so perhaps my "bucket and sticks" shooting style using break barrel springers might be the issue. 

Seems that a larger head size will indeed be the same diameter once "swaged to size" but that material has to go somewhere if there is a varying amount of it. The bearing area of the head contact may thus be greater or lesser as head size varies. Greater=more friction, lesser=less friction. Look at Tom Hollands video-it explains it well. You can disagree with the concept but it is explained well there and it is logical to me. That doesn't make it correct but personally I do agree with the concept as he presents it.

Guys,

For some clarification, I did measure the FPS of larger and smaller headsizes. The larger head pellets almost always had a muzzle velocity that was much lower than a pellet with smaller headsize. I have sorted a full tin or more of pellets, and ran ALL of them through a chronograph. True, most sane people would not go to those extremes, but this dope did. After sorting a second tin of pellets, I shot them through a chronograph, and, at the same time, at a 55 yard target. Almost all pellets with a larger headsize, despite the weight, were always much lower than the nominal group. By inches........MANY inches, like 3, in zero wind conditions.

Also, about the heads of the pellet hitting the choke, thus "sizing" them all consistently, this is true, unless the pellet head is so small, as someone noted above, it isn't made smaller than the choke.

Now, this has a LOT to do with the equation. If a heavier pellet, has a larger head size, it will slow down due to FRICTION before it gets to the choke. And a pellet of smaller headsize will have more velocity before it hits the choke. The smaller headsize pellet will traverse the choke with little resistance. The larger headsize will slow down more, because the excess diameter needs to be compressed by the choke, thus slowing it down. Friction has a lot to do within the delicate world of air perfection.

I've found that with no pellet sorting, out of a 12 ft.lb Field Target rig, I would get around 5-7 "mystery" shots in a match.

Once I began weighing them, that went down to 4-6 mystery shots.

When I did both weighing them, and headsize, it went down to 2-3.

When I weighed, checked headsize, and rolled them (to make sure the skirts were the same), my mystery shots went down to 0-1 per match. For this guy, I've seen a clear difference.

These are my findings,

Hope this clears things up, or maybe stir the pot a little!!

Tom Holland 

Field Target Tech 

LOL......"stir the pot a little", OK lets discuss a couple friendly differences of opinion.

"Almost all pellets with a larger headsize, despite the weight, were always much lower than the nominal group. By inches……..MANY inches, like 3, in zero wind conditions."

Wow, I've played with different springer tune levels for quite a few years and found that a 7.9 grain CPL at 830fps only drops about 1/2" more at 50 yards than when the same springer was tuned to shoot the same pellet at 880fps. I would think that the drop of a low recoil PCP wouldn't be "many inches" at 55 yards. I'm assuming you're attributing the "many inches" of drop due to reduced velocity.

"about the heads of the pellet hitting the choke, thus "sizing" them all consistently"

Hummm....when pellet heads are large enough (not loose fitting) they are "sized" in the leade before they even get to the choke, therefore every pellet entering the barrel starts at the same size. Matter of fact, when testing my HW barrels for consistency I've found "tight spots" midway through the bore that further "sizes" the pellet before it enters the choke. With HW barrels I've usually found a constriction at the barrel pivot block where the barrel is pressed into the pivot block. When my HW springers were new I first checked for "bore constrictions" by pushing new CPLs through the bore with a coated cleaning rod taking note of constrictions before the pellet meets the choke. If there are constrictions "mid bore" I would work these areas with a patch charged with J-B bore paste till the constriction is reduced as determined by new pellets pushed through the bore. The issue with loose fitting pellets is that the pellet heads aren't constricted at any part of the barrel till it gets "sized" at the choke (if pellet head is large enough). If the pellet head isn't "sized" when initially loading into the lead it will "rattle down the bore" with almost no friction till it "hits" the choke. Pellet heads of various sizes that are smaller than the leade will "rattle down the bore" with various amounts of alignment when it enters the choke.

"The larger headsize will slow down more, because the excess diameter needs to be compressed by the choke" and "If a heavier pellet, has a larger head size, it will slow down due to FRICTION before it gets to the choke."

Hummm......not if the pellet head is "sized" when pressed into the leade. It's all "free sailing" till the choke is encountered. Only if the pellet head is too small to be reduced in the leade will this be an issue. 

"a pellet of smaller headsize will have more velocity before it hits the choke"

Interesting, I would think that air loss around an undersized pellet would also affect velocity as well as pellet alignment in the bore. Also, kinda interesting to me that there is concern for loss of velocity if there is better "pellet to bore alignment". Perhaps NEED to sort via sizing and weighing is due to the inconsistencies of the ammo.

"When I weighed, checked headsize, and rolled them (to make sure the skirts were the same), my mystery shots went down to 0-1 per match. For this guy, I've seen a clear difference."

LOL.....my bucket and sticks springer shooting isn't good enough to register even "4-6 mystery shots". With the current course "T" ratings I take more than 4-6 LOTTERY SHOTS not knowing "where that one went" during a match!