GTA
General Discussion To Gateway To Airguns => Gamo Gate => : vinceb July 09, 2006, 02:17:48 PM
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I finally tried something today I had been wanting to for a while... I put a few CPL's in a plastic container with some powdered moly, shook them around for a while, and ran them through wifey's Shadow.
The result? A consistent LOSS of 100-200 fps!
A suspect that this is from the powder "bunching up" in front of the pellet, wedging between the pellet and the barrel, and causing excess drag. Can't imagine the additional weight of the moly dust causing that kind of velocity loss.
That's my best guess, anyway...
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I think it would be the lack of friction that caused the lost of fps.
The pellet was in the barrel a shorter time because of it being slipery = losss of FPS.
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also be interesting to see what others have to say about those results and why. Personally, I don't think it is the moly loading up on the pellet but if it is lubricated so much that it has little resistance moving down the barrel, then the pellet skirt cannot expand to create a seal because of the lack of resistance as it is moving down the barrel. The pressure behind the pellet may not expand the skirt creating a seal. Hey... am I making sense???? :D
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If the pellet spends less time in the barrel, that means it's going faster and the muzzle velocity oughta be higher.
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Do this once, take a pellet that is lubed and push it through the barrel and feel the resistence.
The push an UN - Lubed pellet through the barrel, it should be a lot more friction , that equals more time for the air pressue to build and this equals more velocity !!
CLEAN the barrel First to make things even.
I did this and used an old cleaning rod as a pusher, and there IS a difference.
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The only possible caveat I see is if you mean that the pellet spends more time in the BREACH - letting pressure build up before it starts to move forward. I doubt this is the case simply because most of the initial resistance to movement isn't static friction as such, it's the lead deforming as the pellet is forced into the rifling. And I don't see how moly powder is gonna make much difference there.