Es seems a little high for 10 shots
I finally got around to putting my chronograph to work testing my Edgun. It seems no matter where I set the HST, I am seeing 20+fps Es for 10 shots. My pellet fps has ranged from 10-shot strings at about 940 fps down to 10-shot strings at about 830 fps. 20+ Es. I’s using the 18 grain JSB, but did a 10-shot string with the 15.89. At about 945 fps the gun shot an Es of 21. I get this spread whether starting at a 200 bar fill or starting at 175 bar. This is a certain symptom of… ? Is it the regulator? HS binding?
thanks!
darryl
All Replies
darryl
PS with accuracy being the big issue, if a gun shoots consistently accurate with a shot string and Es similar to what you’ve posted, I’d see no need to dick with it. :smilen:
But dick with it I did…1/16 turn more CW on the reg and HST 1/4 turn less CCW (back to factory setting) resulted in one shot string of 53 shots w/ an ES of 14 fps and 2nd shot string of 57 shots w/ an ES of 17 fps. My velocities were 901 and 897 respectively. I am pleased with this and I note that my regulator setting is really close to Endo’s and Tedd’s settings, mine being 1/4 turn CW from factory 130 bar. My fill is to 200 bar and I’m guessing the gun comes off the regulator @ 115 bar and milks about 5-7 more shots, off the tube, before dropping out of the ES previously mentioned. My usable shot pressure ends about 105 bar consistently. (keep in mind this is a .25 long) I’m guessing that a 220 bar fill will yield in excess of 65 shots with an acceptable ES for long range small target hunting.
Now, to try and get the accuracy to my goal. Wish the damn wind would quit blowing. My 50 yard archery range has light for night work and with the warmer weather, I’m going to see if I can get a calmer environment to seriously work on accuracy, as the wind is my bitch, right now. Doesn’t take much more than a goat fart, to mess things up, when your dealing with POI variation in mms @ 50 yards. I’m realizing that the 1/2″ group, or better, is a very elusive quarry, as I’m leaving to pick up 8 more tins. 😕
HJ, I did check out that post, and supplied al ink to an article on airgun lubes: http://www.pyramydair.com/blog/2005/03/airgun-lubes-the-good-the-bad-and-the-ugly/
Hoot: sure seems to take a beating. Good thing he can dish it out too. This forum seems pretty loose by comparison to some others.
darryl
Hello, hsnmz.
For the accuracy of both guns, mine is good, my friends, not so good.
My gun shooting at 50m out door. Light left to right wind.
5 shot to each target and total of 65 shots.
Average speed is 940ft/s. There were speed drop after No.50, and significant drop, and No.61 is 900ft/s, No.65 is 840ft/s.
So, do not see No.13
I did not dope for the wind, so you can see the tendency of hit zone, constantly little bit to the right.
I guess line is each 1 inch(2.5cm).
My friends gun at 50m in door.
5 shots to each target.
Average speed of 908ft/s.
If you see only one target, it is not so bad. But if you see all of them, you do not see the tendency of hit zone, and CTC is not small.
line seems to be each 1cm.
HJ, I agree with your thinking about the pellet speed being set to around 890 fps. One of the guys here stated in this forum that the Edgun is very accurate with sorted pellets at about 940 fps, and maybe a bit higher. He also pointed out that unsorted pellets perform better at the lower speed you’ve mentioned. I can imagine how these unsorted (greater size and weight deviation) can carry over those greater deviations to affect higher Es and larger grouping at distance if taken beyond their stability speed. Kind of makes sense. Thanks for sharing.
darryl
PS with accuracy being the big issue, if a gun shoots consistently accurate with a shot string and Es similar to what you’ve posted, I’d see no need to dick with it. :smilen:
I have that same curiosity; how large does the Es have to be to impact accuracy?
From my experience, with the Matador .25, 50 yard range and 910 fps, an ES of 30 fps will actually give acceptable grouping. The POI variation, for me, is about .20″ in elevation. POI spread, resulting from the same 30 FPS ES, is .25″ @ 800 fps with my Marauder. Where I am now trying to consistently squeeze sub .5 ” groups @ 50 yards, out of the gun, the ES of 10-15 fps becomes of greater value. I’m not there yet, but I have learned that doping for wind is much more critical than the actual ES. The other issue I note, with my gun, is that the higher the velocity, the greater the ES and the less consistent the accuracy. It seems clear that, greater than 950 fps, my barrel/pellet combination is pushing outside acceptable ES and accuracy for longer ranges and ethical small target kills. For my gun, it is looking more and more like the premier accuracy is going to occur at 890 fps or less, as Tedd and many other’s have indicated. Going to turn my regulator down another 1/8 CW for a lower target velocity, as I shot an amazing string yesterday @ 920 fps with an ES of just under 9 for 46 shots. I’m hoping this results in a similar ES @ 890 – 900 fps and perhaps 55 shots. Might be lucky number 7 times inside the gun that yields what I’m looking for.
I have that same curiosity; how large does the Es have to be to impact accuracy? If one shoots within the sweet spot of starting pressure + optimum shot count (before dropping off the regulator), and can maintain accuracy throughout that shot count, when does ES become an issue for the Edgun?
BTW I really do suspect my failed chronograph.
dear Marco, how about the accuracy of both guns ?
Hello.
Similar issue reported from my friend, so let me join in.
My friends gun has ES of 22ft/s after break in, and the speed does not get higher to 950ft/s by HSTA adjustment.
Two numbers are mine and friends.
Average speed: 935ft/s, 908 ft/s
note:mine can get to 960ft/s by HSTA, this is just then I got the full data.
ES:13 ft/s, 22ft/s
Standard dispersion:2.5ft/s. 5.5ft/s
Pressure loss per shot: 1.6bar, 2.0bar
Flyers: I do not recognize, My friends says there is,10 -30% is noticeable.
So, my friends gun have more speed dispersion although it is lower than mine and lower than 950ft/s, uses more air per shot, and there is flyers.
Better check the regulator leak in this situation?
Marco
hi huntjunky,
I’ll track down that thread. I’d hate to have to tear into it, but that’s part of it’s lure: relatively easy to work on.
thanks!
darryl
Hey Darrel, I know your gun is quite new and like you, I had the same symptoms. My findings and remedy were to clean up the regulator interior. Coincidently I have posted a thread listed as “Just a Tip”, on the matter. In retrospect, I probably should have called the thread “Hoot’s Panties”. 😆 It will all make sense if you read it.
Well, now I can be sure of one thing. My chronograph has bit the dust. I’ll have to order new sensors or buy a new chrony outright. I won’t touch the gun for any fixes until I can get an accurate view of what it’s doing. Square 1
LED lights are a good choice they don’t flicker
I have been using led light on my chrony with same results as outdoor
Darrel what lighting are you using. Most lights flicker at a rate that is faster than the human eye can detect but your chrony will see the flicker. This will change your chrony reading depending on the light cycle. There are lights specially designed for shooting a chrony indoors
- You must be logged in to reply to this topic.
HJ is there anywhere you can shoot for zero inside? Heck I’d love to have your outside shooting area. Keep us posted on how your accuracy testing proceeds. Seems you’ve dropped the speed into the pellet’s stability range for the gun. Some early morning or early evening shooting will help you get where you want to be, I think. Do you use wind flags?
darryl