Refer to this text:
http://www.airsoftsociety.com/forums/f3 ... #post14674
"Putting a 500mm long barrel in a gun with a cylinder designed for a 363mm barrel is looking for trouble. Your cylinder will not have the sufficient air volume to propel the projectile down the entire length of the barrel. "
also in the text it said:
"Test Bed #2 (Long barrel, High FPS, Moderate ROF):
Inner Barrel Length : 600mm (600mm X 0.03937 = 23.622 in, but let’s call it 24”)
FPS: 400 (the golden number for many)
Cyclic Rate: 15 RPS
Calculations:
At 400 FPS, it takes a BB 0.005 seconds to travel 2 feet (24”, or just over 600mm).
[1 second, divided by 400 feet, times 2 feet]
At 15 RPS, a BB is fired once every .066 seconds.
[1 second divided by 15]
At Zero Point (piston release), the BB exits the barrel at approximately 0.005 seconds, leaving 0.061 seconds before the next shot even begins to travel down the barrel.
[0.066 minus 0.005]
The BB is only in the barrel for the first 7.5% of the firing cycle."
so my question is, am i going to have "trouble" if I put a (M16)509mm inner barrel in my KWA M4 that has 400+ fps with .2's?
I ask this because in the equation, with the 400 fps the bb was only in the barrel for 7.5% of the time. so with this, i doesnt really matter how long the barrel is because with 400 FPS the bb is going to be long gone before the cylinder starts to retract..? right?
(and i do use .25's btw. so my FPS is around 380.)