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Thread: Sorted Pellets

  1. #1
    Protea Benchrest (Air) Team '11/'13/'15

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    Attached is a photo of a 1000 JSB 4,5 mm pellets that was air gauged. Marketed by Cometa as "Selected" pellets. I air gauged them and the measurements are expressed in centi meters of water colunm pressure. Dan Brown on US Benchrest Forum first came up with this idea.

    Simply put, I measure the back pressure that is created when air flow over the pellet head by putting it in a taper hole.

    From the photo it is clear that the diameters vary a bit. Taken that the 25,0 mm pressure is equal to 4,52 mm heads. Event though the heads may be the same size the weights still differ per size.

    Gert
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  2. #2
    Protea FT Team '14/'15/'16/'17
    National FT Champ '16

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    Very clever idea! So is this concept based on a Rotameter?
    Last edited by Regy; 02-02-14 at 16:25.
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  3. #3
    Protea Benchrest (Air) Team '11/'13/'15

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    Yes, the pellet acts as the float. Measures the back pressure with a manometer which gives an indicative water pressure reading. I can size about 250 pellets per hour but it takes some doing to keep that up for a couple of hours.

    The main benefit is sorting out the odd sizes.

    Gert
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  4. #4
    REP: Oom A's Airguns

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    What a fantastic excuse for a miss. My manometer must have miss read that pellet.
    Brilliant, I love it.
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  5. #5
    Rest in Peace Uncle Alan 4/11/2016

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    And is there any difference in the point of impact between the 23 and the 27?
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  6. #6
    Sharp Shooter

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    Gert ... would be interesting to shoot 5 pellets from the left and then 5 from the far right ... indoors ... and them compare POI......
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  7. #7
    Protea Benchrest (Air) Team '11/'13/'15

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    Albert, I agree. It will have to be done indoors. I am shooting the same size per target so in theory they should be impacting pretty close. I have found small speed variances between 4,52 and 4,53 pellets.

    Some of the batches that I have measured looks terrible. The diameter vary all over the place with no real peaks. Must be the pellets that are from all the dies put into one batch.

    Smallest variance in the JSB range are the 5 mm pellets. I am assuming that they don't have as many different dies as for the millions of 4,5 and 5,5 mm pellets that is produced.

    H&N pellets in 4,5 and 5 mm measures a very small variance but I have had no success in obtaining good BR accuracies with them outdoors. I have never seen them used in BR competitions so I assume that other shooters have also given upon them.
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  8. #8
    Inactive Member

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    Can you post some pics of the actual process?
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  9. #9
    Protea Benchrest (Air) Team '17/'19

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    Link to Dan's air gauge



    original post
    How I sort pellets - Yellow Airgun Forum Archive
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  10. #10
    Protea Benchrest (Air) Team '11/'13/'15

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    I have air gauged 1000 Cometa pellets and then weight a fair sample of them. On the left is the head diameter sizes expressed in water pressure and at the top the weights.


    Gert

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  11. #11
    Protea Benchrest (Air) Team '15/'17

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    Gert,

    Can you show us what it does to your chrony strings and accuracy - sorted vs. unsorted on weight and head size?

    regards
    Junior
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  12. #12
    Marksman

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    Very interesting, I would love to see this done with some budget pellets and see how the spread would vary compared to these guys
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  13. #13
    Sharp Shooter

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    Wow! What a process, I've never sorted pellets before but would be very interested to see a weight/size comparison... I'd never go this far myself, think that Dallas's "rolling" technique is about the most I'll ever do.
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  14. #14
    Inactive Member

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    Quote Originally Posted by Juniork View Post
    Gert,

    Can you show us what it does to your chrony strings and accuracy - sorted vs. unsorted on weight and head size?

    regards
    Junior
    Any results on accuracy between the different head sizes?
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