Created: 02/06/19 02:15 PMDescription: JSAR Nighthawk.30Notes 1: 4500-2000Notes 2:Distance to Chrono(FT): 1.00Ballistic Coefficient: 1.000Bullet Weight(gr): 50.00Temp: 43 °FBP: 30.23 inHgAltitude: 0.00# FPS FT-LBS PF81 803 71.60 40.15 80 808 72.50 40.40 79 811 73.03 40.55 78 810 72.85 40.50 77 812 73.21 40.60 76 812 73.21 40.60 75 813 73.40 40.65 74 811 73.03 40.55 73 813 73.40 40.65 72 811 73.03 40.55 71 809 72.67 40.45 70 808 72.50 40.40 69 811 73.03 40.55 68 810 72.85 40.50 67 813 73.40 40.65 66 807 72.32 40.35 65 811 73.03 40.55 64 811 73.03 40.55 63 811 73.03 40.55 62 811 73.03 40.55 61 812 73.21 40.60 60 813 73.40 40.65 59 811 73.03 40.55 58 813 73.40 40.65 57 811 73.03 40.55 56 812 73.21 40.60 55 812 73.21 40.60 54 810 72.85 40.50 53 811 73.03 40.55 52 809 72.67 40.45 51 813 73.40 40.65 50 812 73.21 40.60 49 813 73.40 40.65 48 811 73.03 40.55 47 813 73.40 40.65 46 812 73.21 40.60 45 812 73.21 40.60 44 812 73.21 40.60 43 811 73.03 40.55 42 811 73.03 40.55 41 811 73.03 40.55 40 811 73.03 40.55 39 811 73.03 40.55 38 808 72.50 40.40 37 810 72.85 40.50 36 808 72.50 40.40 35 807 72.32 40.35 34 810 72.85 40.50 33 810 72.85 40.50 32 809 72.67 40.45 31 806 72.14 40.30 30 810 72.85 40.50 29 809 72.67 40.45 28 813 73.40 40.65 27 810 72.85 40.50 26 812 73.21 40.60 25 810 72.85 40.50 24 813 73.40 40.65 23 811 73.03 40.55 22 811 73.03 40.55 21 809 72.67 40.45 20 808 72.50 40.40 19 809 72.67 40.45 18 810 72.85 40.50 17 809 72.67 40.45 16 812 73.21 40.60 15 807 72.32 40.35 14 807 72.32 40.35 13 808 72.50 40.40 12 810 72.85 40.50 11 813 73.40 40.65 10 810 72.85 40.50 9 808 72.50 40.40 8 811 73.03 40.55 7 809 72.67 40.45 6 812 73.21 40.60 5 812 73.21 40.60 4 812 73.21 40.60 3 810 72.85 40.50 2 814 73.58 40.70 1 815 73.76 40.75 Average: 810.6 FPSSD: 2.0 FPSMin: 803 FPSMax: 815 FPSSpread: 12 FPSShot/sec: 0.0True MV: 811 FPSGroup Size (in): 0.00
( this is assuming the Raptors plenum is 90cc) (I think this was correct.)
I noticed the Raptor HP says it has a titanium plenum. Does anyone know what the volume of that is?
The plenum on the mini is smaller. If I remember correct someone said it was 60cc. That’s my best guess, I think think the info for that # was in the jsar gate.
Quote from: Jacob_M on April 09, 2020, 09:55:20 AMThe plenum on the mini is smaller. If I remember correct someone said it was 60cc. That’s my best guess, I think think the info for that # was in the jsar gate.Which, unfortunately, is now gone! Oh well, there was a lot of good info there, maybe it will come back one day. Anyhoo, that for clearing that up! I'm looking forward to following your steps to see if I get an improvement over what I already have. You make a good point on the fill pressure to, since UPS seems incapable of delivering a compressor without destroying it, I'm stuck using my little Spark, and it really struggles doing a full 300 BAR fill!
Quote from: Rat Sniper (AKA: PaulT58) on April 09, 2020, 10:05:30 AMQuote from: Jacob_M on April 09, 2020, 09:55:20 AMThe plenum on the mini is smaller. If I remember correct someone said it was 60cc. That’s my best guess, I think think the info for that # was in the jsar gate.Which, unfortunately, is now gone! Oh well, there was a lot of good info there, maybe it will come back one day. Anyhoo, that for clearing that up! I'm looking forward to following your steps to see if I get an improvement over what I already have. You make a good point on the fill pressure to, since UPS seems incapable of delivering a compressor without destroying it, I'm stuck using my little Spark, and it really struggles doing a full 300 BAR fill! There is a OPEN vendor area for all vendors now and for the forseable future but that doesnt stop you from starting a tuning thread in the vendor area to expand apon.
ADJUSTABLE REGULATORI don't know if this will be the same for everyones Raptor, but for mine I feel my gun is MOST consistent when I fill to only 3600-3700psi. Any higher than this and my Extreme spread widens. The reason for this is my regulator pressure will actually be 100 psi HIGHER when my bottle pressure is 4350-3900 psi. My first 10-15 shots will have higher velocities. Once my bottle pressure reaches 3600 psi or so, my reg pressure reads what I set it to. From 3600-3700 psi down all the way to 2000 psi my gun maintains a nice extreme spread for my uses.
The tune that I posted a couple weeks ago, I had a declining shot string. I did the same and waited 5 seconds in-between shots. At that time my hammer and buffer settings were not optimal and I was over dwelling the valve.
Note that even above the setpoint the velocity does not tend to be absolutely flat. This is because most regulators have some “creep”, ie the output pressure is slightly higher when the bottle/HP reservoir is full than when it is just above the setpoint pressure.This difference is probably only 50-100 psi, but if you are tuning regulated PCP airguns on the plateau (blue curve), it may be enough that you see the velocity falling slightly even though you are well above the setpoint.Conversely, if you are tuned on the downslope (10% or more below the plateau velocity – the grey curve), as the bottle pressure falls, and the output pressure creeps downwards, the velocity increases slightly.Then when you hit the setpoint, and the regulator stops regulating, the output pressure starts to drop more rapidly. Then the velocity INCREASES, developing a bell-curve, just like an unregulated PCP. (Because below the setpoint, it is unregulated).At somewhere around 3% below the plateau velocity (the red line – note all these percentages are just an estimate), the gun is operating near the peak pressure of what would be the bell curve at that hammer strike. This makes the velocity very stable over a wide range of pressures, and you should see no trend either up or down to the velocity above the setpoint.
Bob it's colder than average here too, we're even getting a little snow in parts but nothing that'll stick and it's windy too. I might do some chrony work today.
Quote from: Wayne52 on April 10, 2020, 07:30:52 AMBob it's colder than average here too, we're even getting a little snow in parts but nothing that'll stick and it's windy too. I might do some chrony work today.Wayne, most of this week it has been 35-40 degrees and raining, not my type of tuning/shooting weather.
I haven't seen that graph before. That does make perfect sense for my previous tune.For my current tune I might be right on or right below the plateau. + or - 1%. The difference might be a 1/8 turn in the buffer or hammer adjustment. What I have noticed with the balanced valve is getting below the plateau by 3 to 5% introduces more variance shot to shot. Unless there is something else I am missing with the Raptor tune.The report of my shot does sound more efficient. Much better than it was a week ago. Pretty quiet for 58-60fpe.
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