M4 Upgrade Time

[KileyHAZ]

Sweet, best of luck in the upgrade process! One thing to keep in mind, keep the stock barrel handy. It has been my experience that sometimes shorter AEGs have an overly ported cylinder and suffer a lack of performance due to vacuum introduced by the port in the cylinder while the bb is in the barrel. You can clear this up by moving back to the short barrel for a temp fix and then using a unported cylinder with the long barrel when you have a chance to purchase and install the cylinder. It doesn't happen all the time and depends on factors such as barrel length, airseal, cylinder travel time ect, but its worth keeping in mind if you see a performance decrease.

IMO, the best upgrade you can give any gun that is already sporting high FPS is a quality hop up bucking and nub and you have those covered.

[Crono0001]

Sweet, best of luck in the upgrade process! One thing to keep in mind, keep the stock barrel handy. It has been my experience that sometimes shorter AEGs have an overly ported cylinder and suffer a lack of performance due to vacuum introduced by the port in the cylinder while the bb is in the barrel. You can clear this up by moving back to the short barrel for a temp fix and then using a unported cylinder with the long barrel when you have a chance to purchase and install the cylinder. It doesn't happen all the time and depends on factors such as barrel length, airseal, cylinder travel time ect, but its worth keeping in mind if you see a performance decrease.

IMO, the best upgrade you can give any gun that is already sporting high FPS is a quality hop up bucking and nub and you have those covered.

I had linked this:

http://www.airsoftpost.com/product_info ... s_id=25869

Doesn't that cover the cylinder?

[KileyHAZ]

My bad, I missed that one, yep your covered! Can't wait to see where you pan out~!

[Crono0001]

And yea, the cylinder was overly ported alright.

I opened it up and found a huge gaping hole in the side of it. I don't understand why they would intentionally make you lose pressure. Would too much air be detrimental to your rifle?

[KileyHAZ]

And yea, the cylinder was overly ported alright.

I opened it up and found a huge gaping hole in the side of it. I don't understand why they would intentionally make you lose pressure. Would too much air be detrimental to your rifle?

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...

[ryukensfj]

And yea, the cylinder was overly ported alright.

I opened it up and found a huge gaping hole in the side of it. I don't understand why they would intentionally make you lose pressure. Would too much air be detrimental to your rifle?

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...

because the piston will no longer have a bb cushion so it will slam forward almost like dry firing with a shorter barrel.

Btw I believe you will get more fps with a ported cylinder with the same spring with a short barrel because the piston will be travelling faster

[AxisOfOil]

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.

[KileyHAZ]

wow axis, that was a great explanation, I totally get it now. Thanks!

[AxisOfOil]

wow axis, that was a great explanation, I totally get it now. Thanks!

That's what us nerds do. lol.
Why else would you keep a rocket scientist on the boards?

[Jouki]

Good stuff goin on right thurr, Crono-trigger.