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
Enough lights? Too much lighting ?? The device having a PMS ???
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 .. 😉
Is your chrony good? Battery life or enough lights ?
Increase ? I missed that part ..
Have you checked the barrel/load probe o-ring ??
No,’I replaced it a few hundred rounds ago.
How could the o-ring go bad and cause a 200 FPS increase ❓
I shot my old foldup chrono with a 71 gr .25 slug and It still talks to me :whistle:
Lurker, do you have any grommets on your main spring? If so remove them and recheck. :8:
I’m with Kris. Shoot that POS chrony.
Have you checked the barrel/load probe o-ring ??
shoot your chrony and don’t buy another one.
problem solved :2cents:
It must be the solar storm OR did I let an evil spirit into my regulator the otherday ❓
2 days ago I did the 93 shot string DOWN TO ABOUT 118 BAR.
I accepted the average FPS of 910 for a good setting to start testing for groups.
Today was a beautiful day with almost no wind so I filled to 250 BAR and CHRONO’d 11 shots before going to the range.
DARN, the 1st shot was 21 fps below my anticipated 910 but the rest were fairly flat but averaged only 902 fps.
OK, I took the chrono to the range to work things out…
3 ERRORs getting chrono set up with some dark clouds going over.
4th shot 1,009 FPS
5th shot 1,006 FPS DAMN I’VE BEEN ZONK’d
SCREW THAT, turned HST DOWN 1 Turn.
Readings were lower but mixed with about half as many errors
873, 963, 888, 890, 958, :angrymob:
I kept shooting with not bad groups but not as good as a month ago at 910 fps.
It settled into the 920s as I turned it down another 1/2 turn then it droped to 853.
i turned it up 1/4 turn and it got back in the 904 neighborhood after 73 shots.
I remembered that my reg is set a bit high and that 93 shot test I shot below the normal 120 BAR.
Had I let the evil spirit into my reg ❓ ❓ ❓
OK, I re-filled to 220 Bar and continued shooting OK groups with spotty readings due to clouds, 44 shots spread of 19 SD 4.0 and True Muzzle Velocity 905.
Will is settle more or go ZONKers again ❓
Has my previous shooting to 118 BAR with the reg set above 145’ish caused damage requiring a reg rebuild ❓
As an Obama overseas agent it’s my job to know ..
How did you know??? 😳 😳
The biggest culprit for differing fps is the Pellet. If you don’t size them, weigh them and whatnot you’ll never get consistent velocity anyway.
Now – while a couple of fps ( or as the modern World puts it : mps 😉 ) doesn’t much matter at full tilt it definitely does in 12 fpe and 7 fpe limited countries.
I personally don’t give a Rats ass about the deviation as long as it doesn’t affect the POI. Neither do i care whether i get 65 or 75 shots per fill – as long as the useful shots are hitting what i aim at.
I have to correct you all. Everybody seems to be obsessed with getting duplite readings, and having perfectly flat regulated power across the heart of the fill. look at this:
I calculated the difference between the CHANGE of pellet impact height as function of velocity change at the muzzle. It is a function of time of flight.
this depends on the pellet weight/power. ignore calibre only the velocity matters.
around 900fps +_30fps at 50yards the POI drop is half inch ONLY.
at 100yards it is still less than two inches. when 30fps is difference !!!
BAD NEWS. sorry you cant blame the misses at the regulator.
the maths I used, ignore all friction losses or BC, however the result is corrected for these because I am calculating the difference, so both trajectories will be affected by air, or BC the same way. it is close enough approximation.
sorry the consistency is not that important.
It´s hidden behind that pink Velour couch just by the cosy fireplace.
Well mine wasn’t such a great shooter right out of the box, but now it’s really improving. Everyday I shoot it I like it more and more. Lets see where did I put that Cricket…….
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😳 😳 😳 1st I must admit my slight error.
My pre range chrono averaged 902 FPS. At the range 1st 3 shots read ERROR and the 4th and 5th were 1,009 and 1,006.
So I flunked the math test and doubled the increase from 100 to 200.
I guess I added the errors of both 4th and 5th shots. But what the hell, 100 FPS change is bad enough.
I do get Kris’ point about +/- 10 fps or so doesn’t make much difference at 50 yards and keyser made a good point about the clouds. With this chrono I have only used it indoors with a set of IR Light bars. Next time at the range I’ll use the IR light bars as we have AC available at the benches.
I do believe the readings I got were accurate as they respond to HST adjustment.
Zonk’s idea to remove the grommets from the hammer spring made me think about the temperature changes effecting the spring and rubber differently. Could the higher velocity be caused by he hammer interacting with the rubber and rebounding even more than it does from the spring ❓
Dyotat100 offered the suggestion to use heat shrink on the end coils of the spring i stead of grommets. That will be my next experiment.
Kris, with poor hearing I have depended on numbers from my chronographs to achieve what some can do by ear. And until I got this Vulcan I was doubting my rifle shooting abilities. Now if I can get relatively consistent numbers I’ll be able to find the best settings for my best groups. My $6,000.00 hearing aids help only some with understanding speech but leave a lot to be desired.
I actually have better than average hearing at very low frequency and often hear elephants stampeding past Zonk’s place some 60 miles away. :rofl: