| Original Message |
david (Login dvdrit)
Posted Jul 3, 2009 8:25 AM
Quote from Model 48:
I read on a CO2 forum an interesting contradiction, that CO2 pellets deliver higher velocity than lighter pellets. This again appears to defy the laws of physics if on assume that the CO2 delivers the same pressure behind the pellet regardless of pellet weight. However, there where chrony listings to support that this was true. With numerous pellet brands and guns. So what gives -
End of quote.
You have made some interesting observations.
Could it be that since the viscosity of CO2 and air is different and depends on ambient temperature and pressure, that unexpected results were observed?
With regards to other observations on spring performance and different calibres, experiments on any ONE gun can still be pretty inconclusive because its hard to put numerical values on ALL the parameters and dimensions.I have some reservations about how accurately some data can be obtained.
Assuming that the cylinder, T/port, spring and piston are untouched, as soon as the barrel is changed from a 22 to a 177, a whole new set of variables(such as coefficient of pellet friction and fluid dynamics) are introduced.
These will influence any comparisons of bore efficiency using the same power plant.
The barrel is such a fundamental part of an airgun that as soon as it is changed, even in the same calibre, the gun takes on a new character and has to be discovered again.
Its an interesting topic and good luck with your research.
Keep us posted.
D
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