GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => German AirGun Gate => Topic started by: thekid on March 27, 2011, 04:00:20 PM
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Had a little time this morning to take my stuff to the warehouse to do some chrony numbers.
I only shot at 3 yardages 21-30-40.. I used the 34 .177 cphps 7.9, 34 .22 preds 16, 350 .177 cpum 10.5.
34 .22 21 yards (646.2 - 14.8 fpe).. 30 yards (617.1- 13.5 fpe).. 40 yards (569.6 - 11.5 fpe)
34 .177 21 yards ( 792 - 11 fpe).. 30 yards ( 748.1 - 9.8 fpe).. 40 yards ( 710.7 - 8.8 fpe)
350 .177 21 yards ( 830 - 16 fpe).. 30 yards ( 791.6 - 14.6 fpe).. 40 yards ( 720.6 - 12 fpe)
I was unable to stay to long , the 34 .177 and the 350 .177 are stock except home tune.
The 34 .22 has 18 fpe at the muzzle with preds. Rob
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Interesting!
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Thats pretty cool. I resently did the same testing with my 177 350, 470 and Hunter and my 22 350. I chronied 12 in, 10 yds and 28 yds. My 177 350 with vortek kit were just a little higher but I was also shooting 10.2 gr pellets. All this velocity info on here should give people a good idea of what to expect with different pellets. Thanks for sharing the info.
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crony,s are a great tool to have what surprise me the most with a crony. Is that a lot of time heavier pellets will shoot faster then lighter pellets. because of barrel tightest. Down range energy is interesting. Usally the lighter weight pellets lose more energy down range the the mid weight pellets. Glad to see you got the breech fixed on your 34. my 22cal 34 is shooting hot still doing about 730 with 14.3
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Thanks NL, I did as was said and took it slow and I love that I can use rws pellets now with out them getting smashed.
I'll finish off the preds first though. I just thought with all these chrony questions of late, These numbers might help out someone who doesn't have one. And then might be able to judge what game they can take at these yardages.
I was going to go all the way out to 75 yards but my kids called and I had to pack up and head home, nothing major though. Rob
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These tests are very interesting. I used to shoot 8.4 gr jsb out of my 177 350 bit switched to the 10.2 because even though the heavier one started slower at 10 and 28 yds hey were goin faster with more fpe. I didn't think there would be such a difference.
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Onebaddj, That is why I first started using 10.5 gr in the 34.177 it carried the energy that much further I just did not know they are not good for mid powered springers.Rob
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thanks for doing this Rob...its a lot of food for thought cheers Bart
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You might have been even more surprised if you did a short test (say 3 or 5 yards) and compared to the longer ones. High speed .177 are going to drop off pretty sharply above about 900 fps. Heavier pellets will retain more energy.
You might want to look up info on the coefficient of drag. I was surprised what I could find about figuring out impact velocities without ever doing range testing.
Richard
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Here is a ballistic calculator that you can plug your values in and figure your BC for your pellets and gun. The numbers you get might be slightly off from those published, but your is the more accurate way of determining BC (by actually measuring it).
http://www.airgunexpo.com/calc/calc_bcc.cfm? (http://www.airgunexpo.com/calc/calc_bcc.cfm?)
Nathan
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Those energy figures are great.
Thats why the .25 pellets sound like they hit so hard from 40 yds, cause they really do.
Even though they start out in the low 700's---late 600's.
Remember, an object in motion tends to stay in motion. Once 20-30 grains accelerates to a given velocity, the only forces acting against it are drag and gravity.
And the mudhole it eventually stomps in whatever it hits :)
An old dude that used to build hotrods around here used to tell me....Theres no replacement for displacement.
God bless,
Farmer