cylinder

[Phil_Black]

Hi !

I was reading about matching the cyliner and the barell length.

Since i did recived my tight bore, i put it in and noticed that the cylinder of my m4 s-systeme is not ported.

Then i was looking in a site were all the cylinder for m4's were ported.

So now i'm confuesd, is there a chance that the porting was facing inside the gearbox (assuming that there is only 1 hole) or is there no porting at all ?

Any ont have noticed this befor or does have a solution ?

Thank's

[ThunderCactus]

what most people do is have the port facing inside the gearbox, so there is a good chance its ported, if its unported your gun will still shoot fine and have the same FPS, but its like half dry-firing your gun on each shot, and dry firing is very bad for both piston and cylinder head

[CDN_Stalker]

Using a shorter type barrel (like under 470mm or something like that) with a full (non-ported) cylinder will/may (depending on just how short the barrel is) drop the fps by 30fps or more. I know anything under 400mm will have fps loss with a full cylinder, but between 400mm and 500mm it's a grey area for me.

[Phil_Black]

Thank's guys i did not taught about the porting facing inward !?!

[ILLusion]

The M4 S-System, for whatever reason, actually does come with a new plated cylinder that is *unported*, even with the 363mm inner barrel.

I don't know why they chose to do it this way, perhaps the new coating on that cylinder reduces the internal volume? Hard to say, as I never looked too deeply in to it, but it has not seemed to affect performance negatively.

[Phil_Black]

SO

I'm planning to upgrade my m4-s with a new gearbox.

When i will put together parts for this projct shoud i get a ported cylinder or not.

Since it was good to match barell length and porting, what shoud i do now ?

My gess is that i shoud match it since we all know that it work's.