Author Topic: Altitude effect on springer  (Read 1051 times)

mobilehomer

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Altitude effect on springer
« on: March 26, 2016, 09:27:22 AM »
Just a question for fun. Let's use Denver as a comparison to sea level. I'm pretty sure that it would lower fps. But, would the loss of speed caused by less compressible air being drawn in during the cocking stroke be overcome by less resistance of the thinner air? Or, would the speed remain pretty much the same? Just thinking abstractly. I live at about 900 ft., and will probably never go above that.


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Motorhead

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Re: Altitude effect on springer
« Reply #1 on: March 26, 2016, 11:48:15 AM »
In a FIXED volume that is a spring guns firing mechanics ... AIR DENSITY differences will change pressure produced during the firing cycle.

Warm thinner air or higher altitude act the same pretty much reducing power potential where as Cool dense air or low altitude has the highest energy potential.

There is that somewhat grey area thats hard to validate where due to lower resistance of thinner less dense air speed of driven piston creates a slightly faster spike in pressure during the shot and the losses one would calculate become less so  :o

I often pack my HW35 .177 along on camping trips to plink with.  Have shot it extensively at 9000+ Ft elevations having it accurate and powerful enough to still effectively shoot great.

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rsterne

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Re: Altitude effect on springer
« Reply #2 on: March 26, 2016, 12:44:53 PM »
The ambient pressure indeed reduces the peak pressure and the velocity of a Springer, and in fact a Pumper as well (at any given number of pumps).... It does not affect a PCP filled to any given GAUGE pressure, (or CO2, which is temperature dependant) because that is compensated for by the gauge (it is psi above ambient).... Once fired, regardless of the gun firing it, the pellet will meet with less air resistance at higher altitude, and carry a larger percentage of it's velocity and energy to the target.... but starting from a lower velocity in the case of a Springer or Pumper....

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