93 Shot String from .22 Vulcan
From Full 250 BAR to about 118 BAR
QUESTIONS:
1) Where did it drop off Regulation ❓
2) Does the Regulator setting change if the HST is changed ❓
3) Is there a Sweet Spot RANGE within the overall Regulated Range ❓
So here is the DATA in FPS:
901, 913, 909, 909, 908, 907, 912, 909, 905, 907,
905, 906, 908, 909, 910, 909, 905, 905, 908, 909, 907, 906, 907, 909, 909, 912, 907, 907, 910, 908, 909, 910, 909,
(195 BAR @ 33 Shots)
905, 906, 912, 907, 910, 909, 913, 909, 910, 914, 907,
(180 BAR @ 44 Shots)
906, 909, 910, 906, 911, 910, 907, 910, 911, 911, 908,
(165 BAR @ 55 Shots)
905, 915, 910, 913, 911, 913, 909, 909, 914, 912, 909,
(150 BAR @ 66 Shots)
907, 913, 907, 910, 910, 907, 913, 912, 918, 914, 916,
(140 BAR @ 77 Shots)
908, 919, 916, 917, 921, 916, 914, 914, 913, 913, 909,
(125 BAR @ 88 Shots)
910, 904, 902, 895, 895.
(118 BAR @ 93 Shots)
Note; the AT Gauge is not perfectly linear so I fudged a couple a little to give the best estimation.
All Replies
can some one ask sniperqty how to adjust the firing valve spring? what is the logic there?
because maybe with that you can achieve the same, by increasing its tension you will reduce power and the height of the pressure spike at low fill.
but I have no clue how much to tune that.
p.s. normally you DO NOT TOUCH the reg, only in extreme cases when it is really high.
if you fiddle too much => you mess up consistency. and it is dangerous (when the tinkerer is an idiot)
Not an expert, I’m just reading the graph.
I didn’t realize you had adjusted your regulator already. Wow, that really is quite a pressure shift with a 1/4 turn!
Please do post your instructions on pulling the regulator. I’d like to see how you did it for future reference.
Me, I’m pretty happy with where mine is and just plan to turn up the HST a tiny bit to get right on the knee
for flattest FPS through the regulated range. It’s plenty of shots for me at current air consumption.
Then again, we have to remember that a 10 FPS spread isn’t going to do much to POI at 50 yards.
Probably makes 1/3 to 1/4 the error my wavering aim creates in kneeling position.
Forget about off hand. This gun is performing above my level, but it is fun
to adjust out as much mechanical error as possible with our instrumentation.
Too bad we can’t “tune” our holds as easily. Can’t find the POA waver limit
screws anywhere on my arm, shoulder, trunk or legs.
Wow, thanks I didn’t realize it was that much trouble 😳
My day of manipulating data has come and gone. Now my 5 home built computers are piled high and collecting dust.
Actually I have the Regulator turned in 1/4 turn from OEM setting of 71mm to 70.5mm.
You said the reg appeared above 145 bar before and I read that below 120 bar can give more consistency and reduce the twang. At 1st attempt I turned the reg in 1/2 turn to 70mm and that was disastorous. Increasing HST reduced velocity and with it nearly all the way backed out it got up to an inconsistent 850. Then I turned it just 1/4 turn ftom the OEM 71mm to 70.5mm. The current string was the best I could get and with the HSTA about 2 turns out.
The point you indicate as the knee was at about 100 BAR. When it finally nose dived at the last 2 shots the gauge ended up reading 90 BAR.
So, who would of thunk 1/4 turn of the REG would change the setting from 145+ BAR down to 100 BAR. ❓
So, tomorrow I hope to pull the REG one last time and turn it up about 30°. So it should measure about 70.67 mm.
I’m re-writing the instructions kris gave me plus the additional help and my shortcut and will post them after I exhaust myself correcting my most obvious errors.
They say a wise guy has many counselors and I’ve been referred to as a wise guy on many occasions.
Thanks again guykuo for your expert help ❗
Take the comma delimited data and save it as a plant text file (not RTF)
Then open the text file from Excel and import it as text with comma delimiters.
Here is what I read (after deleting the spurious and error data points.
I think you turned up your hammer spring tension a tad and it is now slightly above the knee pressure of the regulator.
One thought I have is whether your tempo between taking shots is varying. I’m trying to keep almost the settling time between shots
consistent to minimize any effects of timing on the hammer spring and regulator fill.
Still, you had two big downward values (764, 757) in your data. I threw those two values out before graphing.
Those two weird values and the errs suggest the chrony has measurement anomalies.
Guykuo,
Is there enough velocity to tell where this REG setting is?
Can you easily enter comma delineated data?
847, 764, err, 826, 820, 823, 823, 821, 822, 820, 822, 823, 818, 820, 820, 830, 820, 818, 808, 819, 818, 819, 819, 831, 813, err, 823, 818, 820, 815, 817, 816, 814, 816, 829, 822, 815, 817, 821, 821, 819, 818, 820, 810, 816, 822, 820, 815, 818, 821, 816, 757, err, 817, err, err, 818, 815, 816, 814, 813, 812, 810, 804, 803, 795, 789.
Here is the end of a shot string with my Air Chrony Mk2, Vulcan .22 using some crossman premiere hollow points. The pellets are a bit light so the fps is high, but I didn’t feel like wasting a bunch of good pellets just to find where my regulator is set.
I didn’t bother entering the early shots because it was basically flat and isn’t needed to find the regulator set point
Looks like my Vulcan .22’s regulator is set at about 130 bar and my hammer spring tension is set a little lower than maximum for the regulator setting. You can clearly see the FPS begin its climb on the graph.
ernest video is pretty good on the cricket about adjusting reg.
but don’t use/stick any metal tools into any holes, be it a transfer port or regulator.
the Vulcan reg needs marking, measuring total length between the jaws of callipers, mine was 71mm set to 90bar, yours will be much longer. quarter or half turn will be enough clockwise on yours.
and don’t forget to reduce the hammer. will waste air if not done.
I was told the Vulcan reg is even more sensitive. well if yours is set to 145 that really needs to come down.i removed my gauge end of the AT and used a clean pvc tube (plumbers stuff) to push the reg out instead of pulling it out.
if you do it, you can install a fishing rod guide/ring onto the locking nut so next time you can fish/ pull it out from the gauge side, so you cont have to remove the cylinder and all the crap
hee?
Kris, if breech o-ring were bad I would expect low or erratic low velocities. I did change it a few hundred rounds ago and haven’t had any puffs of air on the cheek since.
My 1st heat shrink configuration my not reduce twang as much as grommets but the velocities seem settled down even with my untouched regulator set way to high (145+).
Today I will chance running another string but from less than 250 BAR to verify the approximate regulator setting.
I’ll post the results and then begin to disassemble to get at the regulator adjustment. Being my first time inside the air tank I expect it will take me several days.
silly but I ask, the barrel o ring is ok which seals against the pellet probe
hee?
How many Beer did i have before i wrote that rant? Scary stuff .. 😮
Good point 💡 my caldwell chrono asks for feet to chrono in tenths of a foot and gives a corrected True Muzzle Velocity.
As far as mumber of beers I’d say you had just enough. Any less and you’d not have written such a brilliant novel. Any more and you’d of fallen off the bar stool and still be out cold.
Kris, I am working out of a tin of 500 that were both roll sorted into the same tray and then seperated by weight with this 500 all weighing in from 18.0 through 18.9 grain. And everyone knows a bathroom scale doesn’t lie 🙄
Upon advice from Zonk I have removed the 2 grommets from the hammer spring for further testing…but I can’t hear very good so I am continuing the quest to quiet the twang by installing HEAT SHRINK on the end of the hammer spring as suggested by Dyotat100.
Chrony is crap. The most failing of them all. Can’t be trusted : A chronograph version of Ed.
I shot mine to pieces when i got pissed at it.
owning a chrony is BAD THING
100fps? are you sure you dont use some light pellets mixed with heavier one?
Any and all “chronying” their guns with a Chrony should actually be shot in the Ass. That would give as accurate reading as those POS “chronies” people seem to love. Too much light, too little ? Shady or a bit too shady ?? Dark ? Light ?? Where the hell am i ???
A good quality chronograph – recommended by the best ( the same idiots who never got any sane readings anyway ).
As said : Before slashing your throat you should verify everything with a real chronograph. Better yet : Shoot a clip each at four different targets. Is the POI wandering ??
Think about it : You ( try ) to shoot a string. Every third shot is “error “. Bow – tell me how to make any sense of strings like that. Not doable.
As long as the POI doesn’t change : What does it matter if your lousy gun is shooting with no dev in speed OR ; God forbid , 14 fps difference ( according the trustable Chrony ) or not ?
Get real – you’ll never, EVER , find a Gun ( any Gun ) that spita out the bullets/pellets at the exact same FPS.
I’d rather waste my time drinking Beer and let the Wifey fuck me. I know – i’m lazy BUT i have a big enough Dick so i get around ..
EDIT : I need to verify a thing or three : I don’t really think you Chrony Afficionados are stupid. You just miss a chronosome – maybe three – and that’s OK in the La-La Land but … I think most of the Chroniers are Squirrel hunters , right ? I don’t hunt Squirrels , God forbid , and even if i did i wiuldn’t be all too concerned about if i hit one 2millimeters below the eye – or the same amount over.
That would , in my Book , be a dead one. Am i wrong ? No Chrony needed to verify that…
PS Before any of them “Experts” respond i give these Bozos a hint : To get exact readings from any Chronograph you need to have the muzzle of the measured gun at the exact same place every time, the exact same lightning and ,the exact same wind, weather and shit. We had those winds thru 60’s and 70’s , if i remember things correctly so good luck copying them .. 😉
How many Beer did i have before i wrote that rant? Scary stuff .. 😮
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You must not set regulator in 1/4 turn !!!! If you are not sure or if you do not have regulator tester is preferable choose 1/8 turn step for tuning of regulator 😉