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Thread: Spring gun tuning

  1. #1
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    Spring gun tuning

    hi chaps -- Bit confused regarding my HW80 in .177...

    I chron'd it the other day several times just to check .. not bore you with the numbers but it is super consistant for an untuned gun , in my opinion anyways .
    getting readings bang on power 11.8 ftlbs with only 10 fps variation over 20 shots over my F1 chrony.

    Any ways that's great , so wondering way the heck is it so loud and why does it recoil and twang ?? if putting out such god numbers ... its very accurate too if I really do my part , in fact I was surprised but I do have to bench rest it and really get my game on as it is very hold sensitive.

    Any ideas , should I just leave it as is , seems a shame to mess , thinking the piston and spring must be all good or it would,nt read so well

    Thanks

  2. #2
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    It will get smoother and possibly more quiet after a few tins of pellets....

  3. #3
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    Quote Originally Posted by darren m View Post
    hi chaps -- Bit confused regarding my HW80 in .177...

    I chron'd it the other day several times just to check .. not bore you with the numbers but it is super consistant for an untuned gun , in my opinion anyways .
    getting readings bang on power 11.8 ftlbs with only 10 fps variation over 20 shots over my F1 chrony.

    Any ways that's great , so wondering way the heck is it so loud and why does it recoil and twang ?? if putting out such god numbers ... its very accurate too if I really do my part , in fact I was surprised but I do have to bench rest it and really get my game on as it is very hold sensitive.

    Any ideas , should I just leave it as is , seems a shame to mess , thinking the piston and spring must be all good or it would,nt read so well

    Thanks
    New or old rifle? Smoke or no smoke?
    "corners should be round" Theo Evo .22/.177 - Meopta 6x42, DS huntsman classic .20 vortex razor LH 3-15x42 under supervised boingrati tuning by Tony L & Tinbum, HW77 forest green - Nikon prostaff 2-7x32 plex.

  4. #4
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    get plenty pellets throught it mate

  5. #5
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    At 11.8 FT.lbs, Darren, it's a bit too close for comfort.

    What pellets are you using?

    If you were using 8.44 gr pellets, just 7 feet per second will have you at 12.0.

    Now, you can make the '80 much sweeter, depending on how far you want to go.

    The '80, at 30mm bore, has a pretty hefty piston. If you reduced piston weight that would help. And if you were to reduce the stroke, that would also help.

    However, if you generally like it the way it is, and just want to make it a little more refined, I'd be stripping it. Degrease, de-burr and polish. Fit a top hat. If the standard guide is a snug fit on the spring, you could stick with that. If not, an aftermarket guide that fits your spring nicely will help quieten things down. If there's room and if there isn't one already fitted, a piston sleeve will also help towards refining the firing cycle.

    Then I'd be removing or collapsing a coil from the spring to get the power down. If keeping the piston weight and stroke standard, this may make the firing cycle feel a little lazier. But many prefer them like that anyway and the result will be a more refined shooting rifle that's safely below the limit.
    Last edited by TonyL; 18-02-2018 at 08:59 PM.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 4/5, 2024.........BOING!!

  6. #6
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    Boinger Bash!

    Darren, looking at your location, if you can, you really ought to get yourself along to a Boinger Bash, as you will only be a smidge over half an hour's drive away.

    The next one takes place on the weekend 7/8 April.

    It's not a competition, it's an informal get together of springer enthusiasts. Superbly executed with the emphasis on safe fun. Lots of targets to go at at up to 75 yards range. Lots of other springers to see and try and many enthusiastic people on hand to glean information from and share your experience.

    I guarantee you will love it if you can come along.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 4/5, 2024.........BOING!!

  7. #7
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    Quote Originally Posted by rhyslightnin View Post
    New or old rifle? Smoke or no smoke?

    new , no dieseling , very smooth to cock

  8. #8
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    Have a look what spring you got in it, I had a 77 spring in mine, put a ptfe liner in and took the piston weight out, it was better again, but 10.8 instead of 11.8

  9. #9
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    Quote Originally Posted by darren m View Post
    new , no dieseling , very smooth to cock
    I'm no expert on this but if it's new I'd go with what others have said then, either put a few tins through & review it or pull it apart and just de grease & re grease, deburr & polish. Maybe later fit a set of guides & a top hat.
    Not sure how they come from the factory but if it's got washers in it it might be worth taking them out to bring the power down a touch.
    "corners should be round" Theo Evo .22/.177 - Meopta 6x42, DS huntsman classic .20 vortex razor LH 3-15x42 under supervised boingrati tuning by Tony L & Tinbum, HW77 forest green - Nikon prostaff 2-7x32 plex.

  10. #10
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    Quote Originally Posted by TonyL View Post
    At 11.8 FT.lbs, Darren, it's a bit too close for comfort.

    What pellets are you using?

    If you were using 8.44 gr pellets, just 7 feet per second will have you at 12.0.

    Now, you can make the '80 much sweeter, depending on how far you want to go.

    The '80, at 30mm bore, has a pretty hefty piston. If you reduced piston weight that would help. And if you were to reduce the stroke, that would also help.

    However, if you generally like it the way it is, and just want to make it a little more refined, I'd be stripping it. Degrease, de-burr and polish. Fit a top hat. If the standard guide is a snug fit on the spring, you could stick with that. If not, an aftermarket guide that fits your spring nicely will help quieten things down. If there's room and if there isn't one already fitted, a piston sleeve will also help towards refining the firing cycle.

    Then I'd be removing or collapsing a coil from the spring to get the power down. If keeping the piston weight and stroke standard, this may make the firing cycle feel a little lazier. But many prefer them like that anyway and the result will be a more refined shooting rifle that's safely below the limit.

    Hi Tony -- yep I get your drift , using AA field 8.44 , strange 2 separate tins of same pellets gave different fps , one tin was about 5 yrs old and faster by 20fps , putting it even higher , but the second tin a new unopened tin of same pellet kept it at 11.8 level , both ran very well over 20 shots each tin.

    cocks nice and easy , maybe a little bit lazy on firing ... going take it apart and look at the spring guide , just wondering now if its got hw77 internals like in a early forum post I read over the weekend.

    just for reference how tight does the fit of the spring guide need to be when slipped into the spring , should the spring spin on the guide or should the whole lot spin on the block.

    lastly re reducing the stroke , is it as simple as putting a tbt piston extension on to existing piston .

    Thanks

  11. #11
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    Quote Originally Posted by Biglee123 View Post
    Have a look what spring you got in it, I had a 77 spring in mine, put a ptfe liner in and took the piston weight out, it was better again, but 10.8 instead of 11.8
    was just wondering same thing , take it apart and have a look ...
    is yours a newer model and where did you get the liner
    thanks

  12. #12
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    Quote Originally Posted by darren m View Post
    was just wondering same thing , take it apart and have a look ...
    is yours a newer model and where did you get the liner
    thanks
    Yes it the new model with the different cocking link, i have a brand new 80 spring, and its a tight fit in the piston with the original steel liner.
    The ptfe liner I made, you can buy sheets of it off for a couple of quid,I wrapped it around the 77 spring and cut to width, measure length of piston internally and add 10mm, then cut triangles out of one end for it to fit around the latch rod, job done, take that piston weight out, replace with a top hat.
    Weighed piston @ 367g with weight in it, 345 without, could lose some weight on it really, my 77 runs a 200g
    Last edited by Biglee123; 19-02-2018 at 04:32 PM.

  13. #13
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    Quote Originally Posted by darren m View Post
    Hi Tony -- yep I get your drift , using AA field 8.44 , strange 2 separate tins of same pellets gave different fps , one tin was about 5 yrs old and faster by 20fps , putting it even higher , but the second tin a new unopened tin of same pellet kept it at 11.8 level , both ran very well over 20 shots each tin.

    cocks nice and easy , maybe a little bit lazy on firing ... going take it apart and look at the spring guide , just wondering now if its got hw77 internals like in a early forum post I read over the weekend.

    just for reference how tight does the fit of the spring guide need to be when slipped into the spring , should the spring spin on the guide or should the whole lot spin on the block.

    lastly re reducing the stroke , is it as simple as putting a tbt piston extension on to existing piston .

    Thanks
    Hi Darren,

    Re spring guide fit, opinions do seem to vary, but I like them to be a snug "friction fit". So, no slop. But not that tight that you have to virtually hammer the thing in! When the spring compresses, the ID does increase fractionally.

    Re reducing the stroke, the two very easy methods would be to either fit the TBT extension or fit one of the Aussie seals, which are much deeper and also reduce the stroke. I haven't tried either, personally. The more involved way would be to have a longer piston rod made up, but you'll need to be knowing what it's made from and that it's properly heat treated, as you wouldn't want that to let go! ISP supply them for some guns, like the TX. Don't know if they supply HW ones? The other person to ask if you wanted to go down the longer rod route would be NickG on here.
    THE BOINGER BASH AT QUIGLEY HOLLOW. MAKING GREAT MEMORIES SINCE 15th JUNE, 2013.
    NEXT EVENT :- May 4/5, 2024.........BOING!!

  14. #14
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    Quote Originally Posted by Biglee123 View Post
    Yes it the new model with the different cocking link, i have a brand new 80 spring, and its a tight fit in the piston with the original steel liner.
    The ptfe liner I made, you can buy sheets of it off for a couple of quid,I wrapped it around the 77 spring and cut to width, measure length of piston internally and add 10mm, then cut triangles out of one end for it to fit around the latch rod, job done, take that piston weight out, replace with a top hat.
    Weighed piston @ 367g with weight in it, 345 without, could lose some weight on it really, my 77 runs a 200g
    is it still the 80 piston inside ie 30mm

    do you have a picture of the new cocking link please

  15. #15
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    Quote Originally Posted by darren m View Post
    is it still the 80 piston inside ie 30mm

    do you have a picture of the new cocking link please
    Yes its the 30mm hw80 piston in it, can't post attachments but its the shoe with the small nib on it.

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