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Thread: Interesting findings of Walther LP53 and Lucznik

  1. #46
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    Quote Originally Posted by Gerard View Post
    Surely this weight is for a given spring wire gauge, OD, and coil rate, and would shift up or down for even slight variations in the resulting spring strength, no? A stronger spring will push a heavier piston just as fast, where a weaker spring would need a lighter piston to achieve the same piston velocity and resultant pellet velocity. I think.
    And you would be correct in regard of of an 80mm stroke rifle.
    However, at these levels i have found virtually nothing meaningful available from the majority of cut springs that fit it, save for its original duel spring set up with its inherrent problems.
    16 to 17 coils....very slight spacing differences.....making virtually no difference in its short stroke.

    The key is correct guiding and piston weighting.
    Ive run maybe 50 experiments now, including a stock of 10 weights.
    The gun increases continually until the margin of 18 ish grams..is achieved....17 grams....or 19 grams not showing anything to report on with a range of spring types but go 21
    grams and i got a definate 15 fps loss. (the weight of the inverted guide rod down inside the piston with the top hat on the guide ....the opposite way around)
    25 grams resulting in furth losses.....of a slightly longer guide rod i had spun up a few weeks back.
    It suggests the margins are crossed, atleast with 2 Cometa springs and the Protek kit spring.

    Edging downward, 15 grams saw a 15 fps drop.....with my smallest top hat that i first started the project with.
    i found no increase in piston slam....indeed slight improvement of control of secondary recoil over stock.
    This tool requires weighting for sure but only so far.
    A weight of 17 to 19 grams appears to have found the parameters......at least in my experiments

    My final experiments will involve Special delrin work in the form of tiny slip rings machined into a circular groove in the ends of the load baring faces of the top hat and guide....as ultra slip thrusters.
    Its just an idea....i just like messing but my final set up will not include plastic i think.....just playing .
    Last edited by clarky; 04-02-2017 at 06:05 PM.

  2. #47
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    Well I just had another little go with my LP53 and it seems I've confirmed your findings. My added piston weights come to exactly 18 grams and shoots 7.56gr H&N Finale Match wadcutters at an average of 465fps. Adding 2 grams, just barely possible with the space available, dropped velocity to 435fps. Removing all the weight drops velocity to 370fps or so. Going up to 16 grams brings it up to 445fps. Adding a 1mm shim under the spring guide (even 1.2mm hits coil bind before the sear clicks into place) drops velocity to around 455, but becomes erratic, jumping between high 430's and low 460's. So 18 grams added weight and 'just right' preload (about 6mm) from the base of the spring guide are just right for power.

  3. #48
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    Quote Originally Posted by Gerard View Post
    Well I just had another little go with my LP53 and it seems I've confirmed your findings. My added piston weights come to exactly 18 grams and shoots 7.56gr H&N Finale Match wadcutters at an average of 465fps. Adding 2 grams, just barely possible with the space available, dropped velocity to 435fps. Removing all the weight drops velocity to 370fps or so. Going up to 16 grams brings it up to 445fps. Adding a 1mm shim under the spring guide (even 1.2mm hits coil bind before the sear clicks into place) drops velocity to around 455, but becomes erratic, jumping between high 430's and low 460's. So 18 grams added weight and 'just right' preload (about 6mm) from the base of the spring guide are just right for power.
    Wonderful work Gerard and very happy your own work mirrors my findings.
    In microcosom this is likely how it is for all springers....Climbing in performance until a margin is crossed.
    My findings also concluded that anymore weight would only increase the jump of the gun but i found the first 15 grams had virtually killed secondary recoil and improved the accuracy over stock.
    The 25 gram spring guide started to return some slight extra slam ...suggesting i had messed up the balance before i even tried it over the chrony.
    Its just so easy making such adjustments with this gun due to the ease of access.....possibly the easiest gun ever to access the mainspring and guide at any rate.

    The difference in velocity we are getting likely to be pellet choice or piston head condition but seems your within about 25 fps or so of mine.
    Great work

  4. #49
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    Yeah, I just happen to have a supply of the 7.56gr pellets on hand. If all i had were 7gr 'pistol' pellets my tuning adventure would likely turn out just a little differently in terms of springer strength/length and piston weighting. Access certainly is easy! At least it has become so, since epoxying on a larger collar over the mutilated original cap, and the gradual reshaping of the threads to truly round by simply turning the cap off and on a bunch of times with greased threads. It was like an irregular octagon when I bought it, seriously... vise-grips... why, people, just why? But all working smoothly now.

  5. #50
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    Quote Originally Posted by Gerard View Post
    Yeah, I just happen to have a supply of the 7.56gr pellets on hand. If all i had were 7gr 'pistol' pellets my tuning adventure would likely turn out just a little differently in terms of springer strength/length and piston weighting. Access certainly is easy! At least it has become so, since epoxying on a larger collar over the mutilated original cap, and the gradual reshaping of the threads to truly round by simply turning the cap off and on a bunch of times with greased threads. It was like an irregular octagon when I bought it, seriously... vise-grips... why, people, just why? But all working smoothly now.
    im certain ive seen one of those grip cap/ guide rod units going spare on a site somewhere

  6. #51
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    No need on my account. I'm happy with it, and will spray it with epoxy paint and low temperature bake it sometime when I've got a couple of other things needing the toaster oven treatment. Might first use a diamond burr on the Dremel to add knurling, but not decided yet.

  7. #52
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    Clarky - tried to send you a PM, but got this message:
    clarky has exceeded their stored private messages quota and cannot accept further messages until they clear some space.
    How about posting some pics of the LP53K that you built?

  8. #53
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    Quote Originally Posted by Leonardj View Post
    Clarky - tried to send you a PM, but got this message:


    How about posting some pics of the LP53K that you built?
    ok buddy i have deleted my cashe ....you should now be able to send PM
    Send me an email ill post you some .....i do not seem to be allowed to add pics....maybe if i send to you you could add some here .

  9. #54
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    At Clarkys request, a pic of his LP53K:

    http://i649.photobucket.com/albums/u...%20-%2001.jpeg

    And a pic of his tune kit for the LP53:

    http://i649.photobucket.com/albums/u...image%202.jpeg

  10. #55
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    eyebull is offline Even a stopped clock is right twice a day
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    Quote Originally Posted by Leonardj View Post
    At Clarkys request, a pic of his LP53K:

    http://i649.photobucket.com/albums/u...%20-%2001.jpeg
    I really like those proportions!
    Good deals with these members

  11. #56
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    Quote Originally Posted by eyebull View Post
    I really like those proportions!
    thank you for your kind comment..
    ....and thanks Len for adding buddy.

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