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Thread: Short stroke drop in piston for the TX mk3?

  1. #1
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    Short stroke drop in piston for the TX mk3?

    I know, I know, therese been a LOT of talk about shortstroking TX's the last years. So much, that I have problems finding and digesting all the info, so now I hope that some of you guys can help me out...

    I have a .177" TXmk3, delivered to me in FAC configuration(no licence required here in Norway). I have done a fair bit of fiddling with the gun over the last years, different strokes and springs, but it doesnt seem to get as calm as I have been hoping for. My hope/wish is to make a new short stroke piston, and not need to alter the transferport from its original dimensions(TX parts are not that easy to get over here, so I'd like to keep the port unaltered). For sub 12fpe, as I wish to use the gun if I happen to end up shooting FT someday.

    So, the the question is: what would be the optimum stroke, piston weight, sealtype, and spring for this "drop in conversion"?

  2. #2
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    With std port, one of NickG's allly pistons will drop straight in and shoot nice at around 11ish FP

    IIRC around 180g and 77mm stroke. I generally run a somewhat heavier piston with the same stroke, but with a reduced TP/ higher SCR.
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  3. #3
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    Yes I run them at 11.2 They do make 12 dead easy though

  4. #4
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    The LGV piston drops straight in for a 76.2 stroke with a piston weight of 252g using a Weihrauch seal.

    If you use a Vortec red seal instead of a Weighrauch seal the stroke gLes up to 78.2 mm.



    All the best Mick

  5. #5
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    Thanks to all of you!

    Seems like you agree on the stoke at about 77mm, but 180 or 252 grams, thats quite a difference!

    What kind of springs are you guys using?

    The FAC spring that came with the gun seems a bit stiffer than the sub 12fpe springs I have seen in a prosport a guy I know came with.

    I'm thinking to go with a softer thinner wire spring, something dimensionally close to the old meteor springs, does that sound sensible?

  6. #6
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    Quote Originally Posted by evert View Post
    Thanks to all of you!

    Seems like you agree on the stoke at about 77mm, but 180 or 252 grams, thats quite a difference!
    Depends on the port... for stock port I'd go lighter end (200-220g max)
    Always looking for any cheap, interesting, knackered "project" guns. Thanks, JB.

  7. #7
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    Yep, stock port. Thats what I meant with drop in, to keep the gun unaltered exept for a new piston.

  8. #8
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    I treated myself to a TX at Christmas, it had a Tinbum kit fitted & was very sweet to shoot.
    I shall be using the gun for HFT & having read about Nickg's kit (it was the words "very little sight picture movement") that made me keen to try one out.
    I fitted the kit last night & first impressions were, bloody hell thats quick. Power is at 10.9 ish with just one of the spacer/washers fitted.
    Off to the club with it tomorrow for a proper session but early indications are that this is the springer that I have been looking for. Many thanks Nick
    Last edited by nick-nic; 06-02-2016 at 12:34 PM.

  9. #9
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    Quote Originally Posted by nick-nic View Post
    I treated myself to a TX at Christmas, it had a Tinbum kit fitted & was very sweet to shoot.
    I shall be using the gun for HFT & having read about Nickg's kit (it was the words "very little sight picture movement") that made me keen to try one out.
    I fitted the kit last night & first impressions were, bloody hell thats quick. Power is at 10.9 ish with just one of the spacer/washers fitted.
    Off to the club with it tomorrow for a proper session but early indications are that this is the springer that I have been looking for. Many thanks Nick
    So this is one of those lightweight pistons, with an unaltered transferport?

    Can I ask what spring you are using?

  10. #10
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    Quote Originally Posted by evert View Post
    So this is one of those lightweight pistons, with an unaltered transferport?

    Can I ask what spring you are using?
    Yes, lightweight piston, standard t/p, the spring that comes with the kit.

  11. #11
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    Quote Originally Posted by nick-nic View Post
    I treated myself to a TX at Christmas, it had a Tinbum kit fitted & was very sweet to shoot.
    I shall be using the gun for HFT & having read about Nickg's kit (it was the words "very little sight picture movement") that made me keen to try one out.
    I fitted the kit last night & first impressions were, bloody hell thats quick. Power is at 10.9 ish with just one of the spacer/washers fitted.
    Off to the club with it tomorrow for a proper session but early indications are that this is the springer that I have been looking for. Many thanks Nick
    Hi Nick,

    Hope you're okay.

    Yes, I've had the pleasure of a number of Nick's lovely creations at the Bash events and they're really something else. As you say, quick, not harsh and very little sight picture disturbance on many of his various tunes.

    Hope you have a good session with it tomorrow. I will get there a few occasions this year, promise.

    One of my customers lives in Waddington. He owns an Air Arms S400/410/510 (can't quite remember which) and a Brummy Stingray. Every time I see him I keep telling him that he really needs to get himself there. He's only a few minutes down the road (I wish I lived that close) When I last saw him on Thursday, it sounded like he's getting ever closer to making his maiden visit and I've asked him to come and find your good self and Mark for a friendly introduction.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 4/5, 2024.........BOING!!

  12. #12
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    All good thanks Tony.
    Look forward to seeing you sometime this year.The club keeps picking up the odd new member here & there so will be pleased to see your custmer from Waddo.
    Update from TX later this afternoon

  13. #13
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    Wind put paid to anything too meaningful this afternoon but I could see my pellet in flight miss the 45 yarders

  14. #14
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    Sounds like a light piston might might be worth a try then!

  15. #15
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    Put one of the TX-pistons in the lathe, and trimmed off a bit of the tube body, and some of the rear bearing/skirt. Combined with the aluminium front, I am now at 208grams wthout seal or tophat. The stroke is at 85mm, with the rod screwed out a few turns.

    With a delrin tophat and a delrin spacer giving about 8mm more preload, The gun is right at 10,5fpe with 7,9grs exacts. Shotcycle is quick, less recoil than before, an no slammy feel. Success so far!

    Need to prove it on paper...

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