General question. For a higher end springer (R9, HW 30, TX200, etc..) what is considered to be maximum acceptable velocity spread and standard deviation? Thanks.
Extreme Spread and SD data
- Thread starter badger5th
- Start date
ES of 12 and an SD of 4 is pretty typical in my guns over a 20 shot string. Some are slightly lower and some are slightly higher but they all shoot well.
As far as MAXIMUM goes, anything consistently higher than those I start think there is something a a bit off. At a 20fps spread, I can pretty much guarantee something isn't right if the pellets were known good pellets.
As far as MAXIMUM goes, anything consistently higher than those I start think there is something a a bit off. At a 20fps spread, I can pretty much guarantee something isn't right if the pellets were known good pellets.
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Also in a new or rebuilt gun you need about a tin of pellets down the pipe before you even start worrying about measuring spread!
Break in time is a must. After that everything fuggler said is spot on!
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Keep in mind that pellets affect those numbers tremendously. Some pellets will shoot with 20 plus fps ES in the same gun that has an extreme spread of 6 fps with another pellet.
I shoot for single digit ES with good pellets. SD will be 3 fps or less. I pay more attention to accuracy and a steady POI than the chronograph numbers. I've had guns that chrono'd well with certain pellets that were more accurate with pellets that chrono'd worse. Pcps commonly have fourty fps plus ES and somehow still very accurate.
Ps, The numbers I used are for ten shot strings.
I shoot for single digit ES with good pellets. SD will be 3 fps or less. I pay more attention to accuracy and a steady POI than the chronograph numbers. I've had guns that chrono'd well with certain pellets that were more accurate with pellets that chrono'd worse. Pcps commonly have fourty fps plus ES and somehow still very accurate.
Ps, The numbers I used are for ten shot strings.
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Thanks. In my R9 right after the initial break-in I was getting single digit ES and 2-3 fps SD for 10 pellet strings with quality pellets. Recently with the same pellets ES jumped to the low 20's and SD increased to 6-7 fps. Accuracy went down the poop chute as well. I plan to take it down this coming week and look at the spring, piston seal, etc.
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The thing is the accuracy has gone down also. The gun I'm specifically thinking of is my 0.177 R9. After I first got it I was getting the single digit ES and very low SD similar to what you mentioned.
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HW piston seals have a tendency to melt quickly if over lubed from the factory. I would just order a Vortek piston seal now because more than likely that is your issue.
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My HW95L .22 after an ARH kit, Vortek seal, clean/polish & Krytox GPL-205 lube & 4K shots.
Shot again today & modified Excel program some.
| Shot Number | Pellet Weight (gn) | Speed (FPS) | Speed (MPS) | FPE (450240) | FPE (450436.7) | JOULES |
| 1 | 14.66 | 723.0 | 220.37 | 17.020 | 17.013 | 23.076 |
| 2 | 14.66 | 720.0 | 219.46 | 16.879 | 16.872 | 22.885 |
| 3 | 14.66 | 720.0 | 219.46 | 16.879 | 16.872 | 22.885 |
| 4 | 14.66 | 719.0 | 219.15 | 16.832 | 16.825 | 22.821 |
| 5 | 14.66 | 721.0 | 219.76 | 16.926 | 16.919 | 22.949 |
| 6 | 14.66 | 720.0 | 219.46 | 16.879 | 16.872 | 22.885 |
| 7 | 14.66 | 730.0 | 222.50 | 17.351 | 17.344 | 23.525 |
| 8 | 14.66 | 725.0 | 220.98 | 17.115 | 17.107 | 23.204 |
| 9 | 14.66 | 724.0 | 220.68 | 17.067 | 17.060 | 23.140 |
| 10 | 14.66 | 726.0 | 221.28 | 17.162 | 17.154 | 23.268 |
| Mean Values | 14.66 | 722.8 | 220.31 | 17.011 | 17.00 | 23.064 |
Shot again today & modified Excel program some.
| Pellet Rifle performance data results (date 1/09/2023) | |||||||
| Shot Number | Pellet Weight (gn) | Speed (FPS) | Speed (MPS) | FPE (450240) | FPE (450436.7) | Joules | Range (FPS) |
| 1 | 14.66 | 730.0 | 222.50 | 17.351 | 17.344 | 23.525 | 723.0 |
| 2 | 14.66 | 725.0 | 220.98 | 17.115 | 17.107 | 23.204 | 730.0 |
| 3 | 14.66 | 726.0 | 221.28 | 17.162 | 17.154 | 23.268 | |
| 4 | 14.66 | 729.0 | 222.20 | 17.304 | 17.296 | 23.461 | |
| 5 | 14.66 | 729.0 | 222.20 | 17.304 | 17.296 | 23.461 | |
| 6 | 14.66 | 726.0 | 221.28 | 17.162 | 17.154 | 23.268 | |
| 7 | 14.66 | 723.0 | 220.37 | 17.020 | 17.013 | 23.076 | |
| 8 | 14.66 | 723.0 | 220.37 | 17.020 | 17.013 | 23.076 | |
| 9 | 14.66 | 728.0 | 221.89 | 17.256 | 17.249 | 23.396 | |
| 10 | 14.66 | 726.0 | 221.28 | 17.162 | 17.154 | 23.268 | |
| Mean Values | 14.66 | 726.5 | 221.44 | 17.186 | 17.18 | 23.300 | 7.0 |
| FPS = Feet Per Second, MPS = Meters Per Second, FPE = Foot Pounds of Energy. | |||||||
| To convert to Joules multiply FPE by 1.3558, Joules to FPE multiply by .7376 | |||||||
| To convert meters per second, MPS, to FPS = 1M x 3.28084. | |||||||
| To convert feet per second, FPS, to MPS = 1F x .3048. | |||||||
| Calculator THRONIC.COM - Kinetic Energy Calculator | |||||||
| FPE Formula is Pellet weight (gr) x FPS x FPS divided by 450240 or 450436.7. |
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This is spot on. Lately Weihrauchs have been terribly over lubed and burning up piston seals.
You can have excellent accuracy at full power with the Hw95. I have a 15 fpe 177 Hw95 with a Vortek PG2 kit and a 20 caliber R9 with a Maccari full power kit both will shoot better than 1" at 50 yds on a good day. If you don't need the power for hunting or long range by all means crop it. I bought another Hw95 in 22 and I'll probably put a Vortek seal and Maccari kit in it right away.
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Hi Ron, I sent you a question on basically the same question amd found your comment here. I think I have my answer. would you recommend the same type of upgrade for my new 97, put in a Maccari full power kit with a Vortek seaI? want to shoot at 50 yards or even further. Nkrumah
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