KileyHAZ wrote:Its based on barrel length, the more air volume the barrel holds the more cylinder you want utilized, the less barrel the less cylinder. It makes total sense to me when going from a ported cylinder to a full cylinder when upgrading barrels but it still makes me scratch my head in why you would need to port one when moving down to a smaller barrel...
So, assuming that air doesn't compress infinitely (it doesn't... so it's a darn good assumption.
)
When you move a certain volume of air, the bb moves a certain distance in the barrel. It seems there's a good understanding of that.
When you get to the end of the barrel, the additional compressed air vents AROUND the bb. It quickly transitions from straight forward to almost straight sideways (it also forms shock waves and expansion fans... i won't get into that)
So, imagine you're driving a car... at 400fps (like 300mph or so)... and then all of a sudden there's a car doing 25 right in front of you. You switch lanes... fair enough. YOU can do it by yourself. Now imagine you're in bumper to bumper traffic at 300mph. When you try to switch lanes, you hit the car next to you, and then bounce off the side and it's like pinball, and everyone starts randomly hitting the car going 25.
That's how air reacts to the BB when leaving the barrel. It's super turbulent airflow. It's a phenomenon known as 'blowby'. Crowned muzzles help slightly. Boat-tail bullets in real guns help. BB's instead generate van karman vortex streets in front of them, making them more or less wobble back and forth, and have random drag on each side. Super inaccurate.
For a more scientific explanation... i have a post on here that discusses suckback and blowby together. like "the myth of suckback" or something like that.
Also, if you want to be absolutely sure that this stuff happens... talk with the VSR guys that run adjustable HPA rigs. lol.