There is an excellent video out on Airtac's youtube channel.
https://youtu.be/MS_Wsn-sW8I
This is an excellent video with great info. I was pondering about this and something came up.
I am not a ballistician and I hope that someone with more knowledge can give a better perspective.
Lets say we want to push a pellet at 880fps out of a 600mm barrel.
Scenario one: We let a small amount of compressed air at high pressure out through the valve. This starts to push the pellet forward and accelerates the pellet. The volume behind the pellet expands as the pellet moves forward to a point where the air runs out of "spring" . The pellet then have to travel further under its own momentum. If the spring runs out of the air at, say 550mm, the pellet will then decelerate due to friction and even more if there is a choke in the barrel.
So in fact the pellet must be accellerated to much more than 880fps in the barrel in order to decellerate back to 880 when it leaves the barrel with very little air following it out.
Scenario two: Use a little more air at a little lower pressure to keep the pellet accelerating all the way to the muzzle and to reach the muzzle at 880fps before the spring in the air runs out. In fact, I think the spring should run out at about 602 mm.
I think the trick is to get the balance right and there is no real way one can measure this. It is only by trial and error one can reach this balance.
Any informative comments will be valued.
https://youtu.be/MS_Wsn-sW8I
This is an excellent video with great info. I was pondering about this and something came up.
I am not a ballistician and I hope that someone with more knowledge can give a better perspective.
Lets say we want to push a pellet at 880fps out of a 600mm barrel.
Scenario one: We let a small amount of compressed air at high pressure out through the valve. This starts to push the pellet forward and accelerates the pellet. The volume behind the pellet expands as the pellet moves forward to a point where the air runs out of "spring" . The pellet then have to travel further under its own momentum. If the spring runs out of the air at, say 550mm, the pellet will then decelerate due to friction and even more if there is a choke in the barrel.
So in fact the pellet must be accellerated to much more than 880fps in the barrel in order to decellerate back to 880 when it leaves the barrel with very little air following it out.
Scenario two: Use a little more air at a little lower pressure to keep the pellet accelerating all the way to the muzzle and to reach the muzzle at 880fps before the spring in the air runs out. In fact, I think the spring should run out at about 602 mm.
I think the trick is to get the balance right and there is no real way one can measure this. It is only by trial and error one can reach this balance.
Any informative comments will be valued.
