Doesn’t really matter what the factory setting was, it can quite easily be out of balance with the amount of hammer strike.
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Leshiy rises velocity right before regulator drops
- Thread starter barreira
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Before you change the regulator, I'd suggest you find out first the max velocity it can achieve with the hammer spring tension.
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Well no one can really diagnose a problem with missing information as well. Based on the information that was given, the assumption will be that the hammer spring tension is too low for the regulated pressure regardless if it's factory setting or not. I'm not familiar with the gun so I do not know if it has an adjustable HST or if it was changed from the factory. Finding out what the max velocity the gun will do at the current reg pressure setting will at least give more information to go by for people to better advice on which direction to go. That information is needed anyways for a tune such as this. If we're just looking for an easy route, then I'll suggest just increasing the hammer spring tension to the plateau and backing it off 15 FPS from there. That way, the regulator remains stock.
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Answered previously in this very thread
https://www.airgunnation.com/topic/leshiy-rises-velocity-right-before-regulator-pressure/#post-777204
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The Edgun Leshiy has a very easy way to adjust the HST with a hex key and without invasing the gun. I will find out the max. velocity as you suggested.
But,let's say that after I back off the 15fps it's still above the velocity I want. It means that I have to reduce the pressure in regulator and find ou what's max. velocity and back off 15fps...again?
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Today I did a shot string, from 237Bar filling, using Hades .22:
1. 275m/s
2. 281m/s
3. 280m/s
4. 292m/s
5. 277m/s
6. 277m/s
7. 275m/s
8. 278m/s
9. 278m/s
10. 280m/s(166Bar)
11. 288m/s(160Bar)
12. 289m/s(153Bar)
13. 293m/s(147Bar)
14. 294m/s(140Bar)
15. 294m/s(132Bar)
16. 288m/s(123Bar)
Look at shot #4!! And the last 5 shots were almost 20m/s more than the first ones. What's wrong with my Leshiy?
Thanks in advance
Honestly - if you are shooting the Hades out of the tin I would expect this. I have weighed several tins of Hades and the JSB 15.9 pellets and they have some of the worst weight distribution out there ranging from 15.3 grains all the way up to 16.5 grains. This shows in your chrono readings, which all appear to be on reg.
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I don't know, I don't recall ever experiencing a nearly 60fps spread from a tin of JSB anything (.22 Hades included), or even from lesser pellets for that matter. A gross pellet defect may explain a deviation of that magnitude but it's normally in the other direction...a pellet that is malformed and does not seal properly, experiencing blow-by and therefore exiting at a low velocity. Shot #4 in this case is a fast one.
I suppose if it were a peewee, it may achieve that high a velocity. But to be that lightweight means it started as an undersized lead blank. That increases the probability the skirt will be incomplete because that is the last portion of the mold cavity to fill during the swaging operation. If the skirt is incomplete, there will be more blow-by and the velocity will suffer. Granted I won't go so far as to claim it's impossible, just that it's unlikely to be the explanation for shot #4.
I suppose if it were a peewee, it may achieve that high a velocity. But to be that lightweight means it started as an undersized lead blank. That increases the probability the skirt will be incomplete because that is the last portion of the mold cavity to fill during the swaging operation. If the skirt is incomplete, there will be more blow-by and the velocity will suffer. Granted I won't go so far as to claim it's impossible, just that it's unlikely to be the explanation for shot #4.
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I think a 1+ grain difference between pellets could explain a 40-50fps difference depending on the gun and the pellets and the barrel. This isn't a stock EdGun barrel - so we don't really know much about it. Also to bang ~32fpe out of a 320mm barrel that Leshiy is gonna have some kick to it as that's up near it's limits with a 130bar reg.
First thing I would do is back off the fps about 50 down to 850-880 fps - 950 is way to fast for the Hades. The chrono another shot string to see if it tightens up.
Maybe weigh out a handful of pellets too and run a string with +/- 0.1grain weight spread.
First thing I would do is back off the fps about 50 down to 850-880 fps - 950 is way to fast for the Hades. The chrono another shot string to see if it tightens up.
Maybe weigh out a handful of pellets too and run a string with +/- 0.1grain weight spread.
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Well I've done a new shot string,but this time with JSB Heavy 18gr. Here the results:
m/s
245
255.9
254
256.4
257.2
258.9
257.8
248.2
259.5
257.5
256.7
255.9
257.8
265.5 - 168Bar
274.7 - 155Bar
278.2 - 149Bar
279.5 - 143Bar
275.3 - 135Bar
271.2 - 127Bar
The symptoms appear to be the same...
m/s
245
255.9
254
256.4
257.2
258.9
257.8
248.2
259.5
257.5
256.7
255.9
257.8
265.5 - 168Bar
274.7 - 155Bar
278.2 - 149Bar
279.5 - 143Bar
275.3 - 135Bar
271.2 - 127Bar
The symptoms appear to be the same...
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#1 being about 10m/s (~33fps) slow suggests some regulator creep, and its effect is aggravated by insufficient hammer strike.
The slower one in the middle of the string (248.2m/s) could be the same thing if you happened to pause longer before that shot, or it could have been a bad pellet, or an intermittent friction issue with the hammer, or a number of different things.
Then the end of the string shows what we’ve been saying all along: not enough hammer strike for the regulator’s setpoint.
The slower one in the middle of the string (248.2m/s) could be the same thing if you happened to pause longer before that shot, or it could have been a bad pellet, or an intermittent friction issue with the hammer, or a number of different things.
Then the end of the string shows what we’ve been saying all along: not enough hammer strike for the regulator’s setpoint.
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The 248.2m/s shot it was a pause between shots.
I think I'm going to lower thr regulator pressure 20Bar, run the procedure you have been tolding me and see what I get.
I then will post the results.
I think I'm going to lower thr regulator pressure 20Bar, run the procedure you have been tolding me and see what I get.
I then will post the results.
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Here's my regulator full of grease. Should I take the opportunity to change the seal/o'rings?
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I reduced the regulator pressure about 15bar, because if it was at 130Bar OEM, now is at 115bar.
I shot a few shots, and without touching the HST the velocity is the same but is using the double amount of air in each shot.
What does it mean?
I shot a few shots, and without touching the HST the velocity is the same but is using the double amount of air in each shot.
What does it mean?
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It’s easier to knock the valve open now that there is less pressure holding it closed. Therefore you get more lift and dwell, meaning more air consumption.
Always dial the hammer spring tension to 95 - 97% of the maximum velocity to give yourself the best opportunity for consistent velocity. Then try making changes if you feel adventurous.
Always dial the hammer spring tension to 95 - 97% of the maximum velocity to give yourself the best opportunity for consistent velocity. Then try making changes if you feel adventurous.
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