Testing the .177 Pelletgage: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Pelletgage
The Pelletgage comes in .177 caliber at the present. The holes are in a steel plate. A plastic plate above the gage plate helps guide the pellet head to the gage hole.

This report covers:

  • Description
  • The difference is obvious!
  • Head sizes
  • Every shot was perfect

The last test I ran on the .177-caliber Pelletgage (reported in part 3) was unintentionally flawed. I wasn’t sure at the time, but when my results were muddled and I examined the test plan, it was easy to see.

Description

The Pelletgage is a device that measures the diameter of pellet heads, so they can be sorted into groups of similar sizes. Pellets that come in the same package often have a range of different head sizes.

We know pellet head sizes matter to 10-meter target shooters; and Pelletgage inventor, Jerry Cupples, wondered if that advantage might not extend to all pellet guns. He invented the gage so you can measure the head sizes of pellets down to 0.01 millimeters. Read parts 1 through 3 of this report to see how I’ve tested his device so far.

In part 3, the test was unintentionally constructed with bias. I discovered that 7.9-grain Crosman Premier lite pellets in the cardboard box come in 3 different head sizes — 4.53mm, 4.54mm and 4.55 mm. The predominant head size in the box is 4.54mm. I sorted pellets into groups by head size for the last test, and I shot 4 targets. Two were shot with 4.54mm heads, and the other two were shot with an equal mix of 4.53mm and 4.55mm heads. In other words, 5 of each head size were shot for each group. That was the bias in my test plan.

I thought that a group shot with pellets of equal size (4.54mm) would be demonstrably smaller than a group shot with pellets having two different head sizes (4.53mm and 4.55mm). So, I shot two 10-shot groups of 4.54mm heads and two 10-shot groups of an equal mix of 4.53mm and 4.55mm heads. This was all done at 25 yards.

The results of that test were exactly opposite what was expected. The 4.54mm head pellets produced the 2 largest groups, and the two mixed-head groups were the smallest. That lead me to understand that there was probably one pellet of the three that was the most accurate, and it probably had either a 4.53mm or 4.55mm head.

Today, I’m shooting three more 10-shot groups at 25 yards. The test gun remains my TX200 Mark III, which was used in the last test. Today, I’ll shoot one 10-shot group of each head size, with no mixing.

I sorted more pellets using the Pelletgage and then gave three batches of pellets to Edith to put into plastic bags. She marked the bags 1, 2 and 3 and I shot them in that order. All shooting was done with the rifle rested directly on the sandbag, which I’ve determined to be the most accurate way to shoot this particular air rifle. Let’s look at the resulting groups now.

Crosman Premier lite 4.54mm group
This is group 1. Ten pellets went into 0.807 inches between centers at 25 yards.

Crosman Premier lite 4.53mm group
This is group 2. Ten pellets went into 0.241 inches between centers at 25 yards. Yes, there are 10 pellets in that group.

Crosman Premier lite 4.55mm group
This is group 3. Ten pellets went into 0.426 inches between centers at 25 yards.

The difference is obvious!

These groups speak for themselves. Clearly, the pellet used to shoot group 2 is far and away the most accurate pellet. Group 3 pellets made a 10-shot group that is almost double the size of group 2 pellets, and group 1 pellets are much worse. But shoot them all at a target without checking the head sizes first, and the resulting group will probably look okay, even though it’ll be much larger than it could be if only the best group of pellets was used.

Note the small changes in the point of impact as the head sizes changed. Remember folks — these are all the same pellets from a single box! The only difference is their head size, which we wouldn’t know without the Pelletgage.

Head sizes

Now for the head sizes. Group 1 pellets are head size 4.54mm. They are the most common head size in the box. Pellets in group 2 are head size 4.53mm. They are the least common pellets — at least they were this time. Last time I sorted them I found an equal amount of 4.53mm and 4.55mm pellets, but this time it was 2-1 in favor of the 4.55mm heads. That leaves group 3 pellets as the ones with 4.55mm heads.

Every shot was perfect

As I was shooting, I had no idea which pellets were which, so every shot I took was as perfect as I could make it. I could see that the first group was going to be big, but I wanted to be able to tell you that I shot my best, and I did. These results are solid. Of course, they need to be repeated by someone else to gain some credibility; but as far as I’m concerned, they’re rock-solid, and the Pelletgage works as advertised.

I think Jerry Cupples is due some congratulations for what he’s done. He’s given us a precision gage for sorting pellets that really does affect accuracy.

I’m not finished testing this Pelletgage. I want to stretch the range out to 50 yards, and there are still .22-caliber pellets yet to come.

96 thoughts on “Testing the .177 Pelletgage: Part 4

  1. Wow ! This hobby is getting more complicated and involved then I ever dreamed. Your test sure showed how the minute difference in head size of a pellet can make quite a difference. Thanks for the report. Harvey





  2. Great report. So now we know head sizes make a big difference. Seems your TX 200 likes big heads, LOL.
    What about the tail or skirt of the pellet? I always thought this end is even more important than the front end. Do they vary as much?
    Thanks,
    -Yogi


  3. This is really great stuff. I bought some jsb exact 8.44 grain pellets two months ago. One tin was 4.51 mm and the other 4.52 mm. The difference at 50 uards was staggering. Comparable to group 1 and 2 from this test with the 4.52 mm being the obvious winner. I can’t wait for a commercial release of the pellet gage. 🙂


  4. I remember that an old article here about pellet sizing (running the pellet through a die) found that it made no difference in accuracy while here we see that selecting for consistency of head size as manufactured certainly does make a difference in accuracy. What are your theories as to why this seems to be the case? Did things like the old Beeman pellet sizer result in a wide variation of head size or perhaps do damage to the pellet in other ways even if they did give a consistent head size?



    • Hello,

      I think that by running the pellets through that die only reshaped the pellet but the mass it had remained the same as it did not remove any meterial as far as I am aware. So you would have same diameter but same amount of material in the pellet after sizing. Also, I do not know if that die only acted on the skirt instead of the head, that would be the equivalent of neck turning for centerfire rifle cases (with the goal of making the tension gripping the bullet more uniform) which I think was the case with the die you mention but applied to pellets. With this gauge the amount of material for each pellet is possibly sorted along with the weight. That would be an interesting experiment, to weigh every pellet and see if after sorting through the gauge the weight is also consistent. Or your rifle just did not like the pellet size you got from the die. Again, I am not sure if that die resized head, skirt or both.


      • To be honest, you use a sizer as much as a grader as anything else, no target shooter would persevere with a pellet that had to be forced through, H&N and RWS used to sell them as did Anschutz, matched to the size of their competition pellets, as said, no material goes anywhere.



  5. I think this is a massively important piece of kit, people have been using pellet sizers for years to grade their pellets, in fact more so than actually resizing them, basically getting a feel for which pellets are good for their gun by how or if they pass through the sizer and ditching those that are too tight or too loose…this allows an immediate judgement, allows a number to be allotted to the head size you need etc.
    I notice from the website that they now offer four different calibres, hopefully they will start selling in the UK or I’m going to have to import a couple!


  6. Thank you for accuracy of this report! As always! I know competition shooters that believe in re-sizing pellets! Pelletgage and re-sizing are not the same and should not be confused or compared to each other! This may change manufacturing of and use of pellets from top to bottom! What about the R 10 pellets etc.? I would think that it would make a difference for hunters as well as competitive shooters in small clubs around the country? I want the best for my bang! Regardless! While entertaining myself or competing and hunting! Semper fi!


  7. B.B.,

    Nice shooting ! Having the TX in .22, the best I have got is .625″ at 25 yds. I am very happy to see you discovered the “flaw” and got some real data driven results. In future testing it would seem that testing 10 of the same head size would be the way to go. Looking forwards to future testing.

    Would love to see a test of the TX 200 MarkIII in .22 sometime if you could ever swing it. “Set the bar” for me ,…so to speak.

    Chris



    • Thank you, Chris. It has been fun overall. Several revisions, great feedback from a few key early adopters, and a lot of trips to the Post Office.

      I think there is a variability in the manufacturer’s processing and inspection that serious shooters have all known about, and dealt with in many ways. Having a way to get actual numbers about this is vital to remove the doubt about which pellet is best. Maybe the manufacturers will act to make this needless in the longer range. There was an interesting report online from Cliff Tharp a week or so ago:

      http://varmintair.typepad.com/varmintairs_blog/2015/06/okay-lets-get-real-about-head-sizes-and-pellet-weights.html


      • Hi Jerry,

        I just read the article by Cliff… WOW!

        I am going to add a big THANK YOU to Chris’s congratulations to you!

        Think that airgunners are going to be pleased having the option to check their pellets, the manufacturers may be a bit less than pleased when their lack of process control becomes general knowledge.

        You have let the cat out of the bag!

        Vana2


      • JerryC,

        Thanks for the link. I read the article and saved the site to favorites for further review. Depressing…..

        I have weighed and head sorted, but not to the extent you have. Thanks for your work and efforts.

        I just hope the pellet mfgrs. sit up and take notice. As Vana2 said,….”the cat is out of the bag”,…and from the looks of it,…..that kitty is none too happy ! (kitty = us)

        Chris


  8. I recently purchased a pelletgage to see if sizing was worthwhile – so let’s look at my experience:
    Using JSB 4.52 Diablo pellets straight from the tin not sized in my .177 springer the chrony recorded MPS 236.9, 238.3, 229.4, 230.5, 232.8, 244.1, 239.7, 238.5, 239.5, 235.5, 240.2, 237.4 for which there was a spread of 13.6 MPS. Then I went upstairs and picked up a can that I had sized using the pelletgage. The readings were – MPS 240.2, 239.5, 237.4, 239.3, 239.0, 236.7, 236.7, 238.3, 240.0, 239.0, 238.1 239.5, for which there was a spread of 3.5 MPS. Ok, you can play with numbers to come up with all sorts of analysis, but logic would suggest that the smaller the spread in MPS the more consistent the result. In my opinion this is a great accessory for the air gun enthusiast.

    Read more: http://airgungurus.boards.net/thread/675/pellets-size#ixzz3dxtUD9Pc



    • Hello, RR and all,

      There are small engraved markings in the metal like “4.52” under each aperture to indicate the inside diameter.

      The laser cut plates made for Pelletgage prior to June 2 were found to be smaller by exactly 0.010 mm (long story) than indicated.

      All who have purchased one of these were contacted to fully explain and offer alternatives to resolve this, including replacement. This error does not affect the precision of the cuts or the incremental size difference of the

      Testing with class x metric plug gages show that the ID of the apertures is within +/-0.00025 mm of the indicated size. There are now five sizes offered, .177, .20, .22, .25, and ,30 on the pelletgage.com webstore.


      • JerryC,

        I had purchased your Pelletgage in .177 caliber last month. It was shipped on 5/18/15 and I have not had the time to use it yet. I checked through all of my emails and did not see any other ones from you except the one stating that it had been shipped.

        So as it stands, the original gage, corrected, will measure from 4.46 mm to 4.55 mm with the upper right hand hole marked 4.51 mm actually being 4.50 mm in diameter, not a major problem.

        Sincerely,
        Bugbuster


    • RR, reading my reply, maybe I am not answering well – yes – it affects all the sizes in the same way, the marking was different on every aperture by +.010 mm, and yes, it is now corrected for all new stock since June 2.


      • Hi JerryC

        The Pelletgage is now at the top of my “must have” list. 🙂

        I didn’t see the Pelletgage on the PA site, do you have a Canadian distributor?

        Vana2


    • RR,

      Jerry C. did measure his .22 Pelletgages and discovered the 0.01mm offset did carry over.

      It has been corrected now and the gages being sold are marked correctly. Jerry also sent out a detailed email to all original gage owners advising of the size difference.

      B.B.


      • I received the email, responded with a don’t worry about it and yet I got a letter in the mail with the corrected number on a sticker strip anyways. Thank you Jerry.


  9. B.B.,

    Oh no! Now you’ve done it! I fear you have, anyway. You might have just laid the seeds for a Cobra Effect (or Streisand Effect or Peltzman Effect — I can never keep them all straight). From now on we might see classified ads on air gun web sites for “the especially desirable 4.43mm 7.9 grain Crosman Premier Light pellets, hand sorted through a pelletgage for the much sought-after 4.43 head size.”

    Never mind that for these pellets to be “much sought-after” the seeker would need to own a TX200. Make that YOUR TX200!

    Michael



  10. BB and all,

    I can confirm similar results in tests of sorted .22 pellets. If I could post pictures here I would.

    One clarification though that I think is in order: this is really a test of the impact of head size on your TX, not of the Pelletgage itself. The Pelletgage is used to determine the head size of the pellets and thus is a key part of the test (in fact the main thing that you want to test), but the results as shown are for your specific gun. Of course, by simple logical deduction, these results indicate that the Pelletgage is doing its job sorting the pellets quite well.

    I think Jerry has a great product here, and I really like and trust my Pelletgage, but different guns and different barrels will react differently to variations in pellet head size in total, and potentially more so with different pellets too. I just don’t want somebody to think their gage is not working if they don’t see the same dramatic results that you got with your TX. My results were not as dramatic with my Hammer Forged barreled Marauder, probably because of the reduced impact of dwell time on harmonics – but I still see a difference.

    So great test. But there are two conclusions here: 1) the Pelletgage works as intended to allow one to sort pellets to achieve an individual gun’s best results (if head size matters for that gun and pellet combination), and 2) your TX is sensitive enough to head size that a change of 0.01mm can more than double the resulting group size with CPLs. Result one will always hold true; result two varies by gun and pellet.

    Thanks for all the great info!

    Alan



  11. Hi BB

    I had wondered what your reasoning was to use mixed sizes of pellets on one target. 🙂

    OK, I’m jumping to a couple of conclusions here and throwing them on the table for comments…

    Seems the best approach to finding the golden pellet for a rifle is to buy premium MATCH quality pellets in 4.50, 4.51, 4.52 and 4.53 sizes and run tests to see what shoots best.

    Then try different brands/styles/weights of pellets of the correct size to determine the optimum pellet for harmonics of the particular rifle.

    For general use, sort pellets for precision work like sighting in and use the culls for hunting feral cans.

    For serious precision shooting use match pellets and sort as required to suit.

    IMHO, I think that any accuracy testing of a rifle should be based on its preferred pellet size in different weights rather than brands of pellets and that only premium (or sorted) pellets be used.

    I like 10 shots groups but unless using sorted pellets I feel that only the best 8 or 9 shots should be used to determine group size as the fliers are likely to be non-conformists doing their own thing.

    …just my 2 cents

    Vana2


  12. I’m still not sure why, in the first experiment, head sizes of 4.53 and 4.55 were mixed and what factor(s) were chosen to determine the bias direction? It seems to me that the first experiment would be the testing of each sorted size.


    • Chris S.,

      As I said, that test was biased unintentionally. I thought that shooting a group of mixed head sizes would be worst than shooting pellets of the same head size. Fortunately for all of us, the pellets of the same head size turned out to shoot the worst in my rifle, which lead me to conduct today’s test and discover the right way to test.

      B.B.



    • Brent,

      All Crosman lead pellets are made of the same lead alloy that contains antimony. Crosman buys lead which they make into slugs called preforms. All their pellets are made from those preforms, which is why the calibers all weigh similar weights. In other words, a Prelier lite weighs 7.9 grains, but so does a Super Match wadcutter, a Destroyer and a Premier hollowpoint.

      B.B.


  13. Congratulations, B.B.,
    Looks like a very successful implementation and demonstration of a pellet sorting method and functional test of a new product.
    It creates a new problem: what to do with all those pellet sizes that DONT shoot well!

    Good job, refining your methods and coming through with the goods.


  14. Two more thoughts.

    Weigh the pellets after sorting the head size with the pellet gauge and see if the weight varies by head size.

    Also check overall length of the pellets for variation in length and weight.

    That can have a effect on the pellets grouping good or not. But I do believe that the pellet head size to the fit of the barrel probably makes the most difference.

    But just think what that pellet will do if the pellet length is short and weighs less with a smaller head diameter than other pellets in the tin.

    The pellet gauge is great for sure but there or still other variables in the pellets other dimensions that could affect the pellets flight. If you want accuracy then you need to sort head size among the other things. Just my 2 cents worth.


  15. Convincing results. I have one question? As head size varies, does the weight of the pellet. It’d be interesting to see if common head sizes are common weights, with other head sizes being different weights. I assume that you believe that head size is more important than weight when it comes to accuracy/consistency.


  16. If accuracy is important to you read Cliff Tharp’s report on Pelletgage. He confirmed the results I am getting. Pellet head diameters are all over the place and not just for discount store pellets. I do have a tin of H&N Finale Match Rifle in.177 cal that is close to perfect. Can’t say the same for their Trophy pellets. I will sort all my pellets until no longer necessary.
    Rocket


  17. So the magical cardboard boxes of premiers all from the same die don’t seem that much different from the cans. I always thought that was a bunch of hooey, but airgunners love their arcane knowledge. I’ve enjoyed the pellet gage almost as much as finding the msds for pellgunoil :)!

    Would you consider testing the field pointed hunting pellets with the gage? I really think they would benefit significantly from sorting by head size.


  18. B.B.,

    What ARE your thoughts on a skirt’s diameter and it’s impact ?

    While both heads and skirts are effectivly “sized” by one’s own particular gun,….(Interfearence Fit) would also play into both.

    Chris


  19. Matt 61, I have been busy and just looked at some of the posts from the last few days.

    You said, “Mike, I hope you enjoyed your cowboy action shooting. Here’s a technique question. My quick draw technique is drawn from none other than Wild Bill Hickok himself who advocated aiming your shot by pushing the gun toward the target before shooting. He considered this to be a worthwhile tradeoff for the extra time, and he used this method to shoot some guy at 75 yards. The pushing of the gun is also embedded in the two handed quick draw technique for modern pistols which involves joining the hands at the midsection and thrusting forward.
    On the other hand, cowboy action events that I’ve seen seem to favor quick response by rotating the pistol out of the holster at the hip, Clint Eastwood style. So, which method do you use?”

    I shoot more like Wild Bill only with two hands. I don’t try to be real fast, just smooth and make the first shot a hit.
    I take a little extra time with the first shot and the last shot. Those seem to be the ones missed the most by folks.

    I also note your comments on the AK rifle. I just wanted to say that my groups of 2 inches were shot with a handload. The rifle will not shoot that well with military ammo. With the best of them it is more like 4 inches. A good AR-15 is going to be more accurate. I have those rifles too. With the AK, you give up some accuracy for stone cold reliability. You pay you money and take your chances. All in all, it’s great fun shooting them both. It looks like our club is going to start shooting three gun matches. More good times for sure!

    Mike


  20. B.B.,

    Have you weighed the pellets of each size to see if pellets of the same size weigh app. the same? I’m wondering if the primary reason for different weight pellets from the same tin is due to the head size and not something else.

    G&G


  21. My elder brother’s gage prompted me to size sort several varieties of pellets that had been previously sorted for weight. Uniform weight did not predict more uniform head size compared to the same pellets not previously sorted by weight.

    Uniform head diameter was more important than weight for consistent velocity. Significantly lower standard deviation for 10-shot strings of .20 cal JSB’s over the chrony when sorted for head diameter, both with and without sorting by weight

    IMO, 1) uniform head diameter is critical to achieve a uniform initial pressure required to initiate pellet movement down the bore with both PCP and sprinters. That variable — minor diameter differences affecting static friction coefficient in the breech — is much more greater than minor differences in pellet mass in determining the pellet velocity at the muzzle

    No doubt variations and dings in the skirt can also result in erratic pellet flight, but all else equal, head diameter is the more important factor, IMO. Erratic flight at non uniform muzzle velocity is the worst of both worlds.


    • TC
      Have you done any testing with waist and skirt diameter or overall pellet legnth in how it affects grouping.

      Not nesicerily chrony readings but actually groups shot after screening through some pellets and segregating them.


      • GF,

        You have mentioned (waist) and (skirt) data as well (length),……Have you done any testing with these? If so,…what are your conclusions?

        Thanks,….Chris


        • Chris, USA
          Yes I have tested all those dimensions you just mentioned including head size.

          Head size did make the most difference. The skirt diameters being different did cause the groups to change also. If the skirt fit the barrel better the pellet sealed better. If it fit loose that pellet usually hit lower in the group.

          The waist of the pellet was a little more tricky. It affected the pellet the farther out I shot. In other words if I had some pellets with different diameter waists the pellet would hit lower if the waist had a smaller diameter. I guess more induced drag than a pellet with a bigger waist diameter.

          Take a look at the JSB exact .177 caliber 10.34 grn pellet. I think when you take a look at each of the features of that pellet that we are talking about you will see why I like that pellet.

          And another thing to look at that is even harder to measure unless you have indicator and base to measure with. And that is the waist location from the front of the head. And inside the pellet to the front of the head. If those dimensions are varying then you will not have accurate groups.

          Again it’s all about how far you want to go to get good groups. If I was competion shooting I would go through all these steps to make sure I had enough consistent pellets for a mach.

          If I’m shooting for fun then no I wouldn’t go to this extreme. And the only other reason I would do all the measuring and sorting would be to learn how each feature makes a difference for how the pellet performs.

          It’s just all about how far do you want to go.


          • GF,

            All great info. Notes made. I will check out the 10.34 for reference on “ideal”.

            I can tell that you have put some time and effort, “far and above” the usual, in finding the “secrets” of pellet design. Of course, being a machinist “might” have something to do with that. 😉

            I bet you dream of a CNC multi-task machine the inputs lead slugs and spits out custom made pellets at 1000/per minute !

            Thanks again,…VERY RARE info.,…..Chris





  22. To bad that pellets come in to many different lengths and skirt and waist diameters.

    If they had specific sizes like pellet head diameters a go and no go gage could be made to check that.

    Oh well guess just have to stay with calipers and blade micrometers for checking those dimensions.

    All in the name of accuracy you know.



      • Reb
        There’s so many different designs it would be hard to make gages for some of the dimensions.

        The best way would be just measure the pellets you have in front of you. You could use the head gage that BB is testing to get the correct head size figured out for the gun you will shoot them out of.

        Then you could mic or caliper them for over all legnth. And categorize them. After that check skirt diameters. Again catagorze them in groups.

        And then the waist diameter. Alot of people don’t realize how critical that dimension is.
        That is designed into the pellet to make drag which stabilizes the pellet. If you have variation there in size your going to have different ways the peeler will fly.

        So the way to get the most accurate groups is to get all the dimensions checked and shoot a group of the segragated pellets that have all the dimensions close to the same.

        That way when you shoot you can make notes and find out what pellets work the best

        And you can go as deep as you want in figuring out the best pellets for your gun. Or you can go the other way and just have fun and shoot as you grab the pellets out of the tin. It all depends what you want out of your gun.




    • Reb
      Rest your case about what. These crazy phones.

      You know what I would rather use my phone than my lap top now. Out in the country where I live now they don’t have cable. The best we can get is satellite. We had cable for years and once you get use to cable and how fast it is its hard to go to the slow internet. It drives me crazy to wait for my pc to load a website or page.

      I pretty much like my phone if I could just get it to agree with what I say.


  23. Info from an email I sent brother Jerry C earlier. Data regarding the .20 cal Pelletgage testing.
    ____

    Two Beeman FTS .20 pellets out of a weighed partial tin of Beeman FTS pellets marked 11.18gr (weighed on a Gem Pro 50 digital scale) crossed the ProChronograph at 747 and 751 FPS, so that’s 14 Ft-Lb out of a gas ram .20 ga air rifle.

    Decided I’d sort the rest of the partial tin of pellets for head size:

    [IMG]http://i306.photobucket.com/albums/nn270/tcups/P1010870.jpg[/IMG]
    P1010870.jpeg

    The first 50 pellets had what looked to be a bi-modal head size distribution. Wondered if they might be from two different manufacturing dies. Remembered your comments about a fellow who used a Dremel grinder bit, hand held, to take the edge off his pellet gage. Looked at that and decided I’d try, instead, just using a felt tip Dremel polishing buff and some Flitz metal polish to make sure that there wasn’t a burr on the 5.07 mm aperture. After polishing the gage, I sorted the remainder of the pellets.

    Notice also that I took the plastic bezel of the pellet gage and interposed it between the steel gage and the protective plastic aperture to make a “stand off” that would guide the pellets, centered, into the gage when I dropped them. This resulted, IMO, in a much more reproducible go/no go measurement. The problem of then getting the pellet to drop back out of the gage once the head passed through was pretty easily solved by using a Q-tip to guide the skirt end of the pellet back out of the gage. Pretty quick way to do it, actually.

    I then sized the next 50 or so pellets (I confess I haven’t yet counted) through the polished gage. No tendency to measure the pellet head size, overall, as “smaller” after polishing the apertures, and no change in the apparent bi-modal head size distribution.

    The test pellets will be the 5.06 mm and 5.08 mm pellets, all of uniform 11.18 gr weight. Testing, over the chronometer for uniform velocity, for 5-shot group size will have to wait for a while. I feel very confident that I got good sizing results and that the sized/weighed pellets should perform well, compared to 5-shot groups from un-weighed, un-sized 5-shot groups from the same lot (I have two sleves of these pellets from the same lot, most unopened).

    I should stop to count so the data will be compelte . . .

    First group, un-polished pellet gage, size (mm) – weight (grains), n=49

    5.05 – 3
    5.06 – 19
    5.07 – 5
    5.08 – 12
    5.09 – 10

    Second group, polished pellet gage, size (mm) – weight (grains), n=53

    5.05 – 1
    5.06 – 18
    5.07 – 4
    5.08 – 19
    5.09 – 10
    5.10 – 1

    So, it looks like I have 102 x 11.18 gr test pellets with 3 dominant groups:
    37@ 5.06 mm
    31 @ 5.08 mm
    20 @ 5.09 mm

    Uniform weight didn’t predict uniform head size.

    More later.

    tec


    • Tommy C.,

      Thank you for that test. While not to your extent, I did (not) find a correlation of weight and head size as well.

      I just got an HO kit for a TX 200, after getting the 12fpe. kit. Will most likely install the HO this week end.

      Question,….Have you done test to see how much rotation a spring has during compression? I did one this past weekend and found the spring only rotated a max. of 32 degrees in 4″ of compression. If having done test, what is your findings on rotation? Is my test in the “ballpark” ?

      Thanks, Chris


  24. This looks really awesome. Somebody may have already answered this but if you had to pick between getting one of these and getting some scales to weight pellets, which would be the best way to go?

    Cheers


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