Airsoft Forums UK

imho - if you did it would only be very very slightly

The BB would start to move the moment the air pressure builds enough to shift it from its position under the nub/bucking...

After that the BB is travelling down the barrel with only minor drag on the barrel meaning little resistance to the piston in cylinder after the BB moves away from nub

You are creating more air or tailwind behind the BB when you increase the volume, that is true but as I see it the increase is really on the tailwind of BB (as BB travels along barrel with minor compression resistance)

I hate the Type A, B, C, D cylinder bollox as it is very vague at the best of times

and air volume calculators over complicate stuff also

Measure the start of hole of port from front

subtract say:

15mm on 0.20's

or

17.5mm on 0.25's

or

20mm on .28's/.30's etc...

What value is left multiply by 10 = ballpark barrel length/BB's

EG: 50mm - 17.5mm (0.25's being used) = 32.5mm x 10 = 325mm

Cylinder port/volume is about right for a 325mm barrel on 0.25's

(I'd use this cylinder up to say a 300mm barrel or a smidge over)

if you are cycling that quick then you should be SS 2 or 3 teeth

& if SS then barrel will be shorter than a full stroke 455mm AK barrel

On a 8t DSG the piston o-ring will just show briefly in a 43mm port at full retraction

43mm - 17.5mm = 25.5 x 10 = 255

& a 255 barrel in a G36c is about the limit for volume on 8t DSG

Hence many DSG's are shorter barrel builds like stubby M4's AK74 G36 etc...

(275+ would require an expensive 9t DSG)

long winded bollox pt2:







something amongst all that crap should help you decide on cylinder port

and if a slight increase will not imho effect PME risk too much as extra stroke is pushing the BB down the barrel with only minor drag

This might increase a little if you increasing volume to use heavier BB's as it would be a heavier mass, so might take slightly longer to shift from under nub perhaps but only very slightly again

soz can't give a more accurate answer

but think the risk is only slight as it pushes down the barrel with greater volume

what barrel/cylinder/stroke are you jumping up to ???

too much information to understand on a Monday morning tbf

Running an ARP-9 with the stock cylinder (hole in the middle, so about half the effective V2 volume) and a 229mm 6.03 barrel. I lost roughly 0.2J just with the barrel swap, and it works kinda fine on 0.25s, but of course the range is the same as 0.2s because of the lack of air behind the bb.

Now though I have changed the hop rubber to a ML MR-Hop and I want to use 0.28/0.3g bbs to maximize the range and consistency, but as stated above the cylinder volume isn't enough.

The stroke is full, I have just removed the 1st tooth after the pickup because the stock piston (which exploded not long ago btw) didn't have it.

I guess I'll just buy a new cylinder (3/4 hole) and see what happens, piston has plastic teeth anyway so if it explodes it won't strip the gears  cheers mate

In that case I'd be tempted to SS 3 teeth,

(go up to a m10 or m15 higher spring to compensate)

but see how you go...

All this SS bollox was what TM did with their High Cycle guns

to run quick at 300fps guns without smashing up

they just gave their high speed set, the sector gear 13 teeth than the usual 16 teeth...



or



(fairy dust not included btw)

see how you go, think you should be OK but plenty of scope to short stroke

(hey I'm a poet & I didn't even know it)

Thanks for the information

I'll slap the new cylinder (found a full one in my box o' bits) in as soon as I get the chance and test, if it fails then the whole system's going to be short stroked or HPA'd once I find the courage to drop €600 on a kit.

You'll never need a full cylinder for short-ish barrel like that

the full cylinder would be for an AK or if you wanted max volume on a 375mm+ gun

in the 375mm barrel gun you'd probably have a 3/4 or 4/5th type cylinder

(front of port somewhere around 50mm from cylinder head)

That is really what ya want imho

and if you SS you want the piston to just peek past the port to fill the cylinder with air quickly in a snappy build

(a full cylinder will rely on the cylinder filling by air passing past the o-ring)

So imho - no you do not want a complete full cylinder, but a ported one, just with a bit more volume etc...

I don't know what the fuck is wrong as I can't receive status notifications.

But anyway, I lied, the current cylinder has a 3/4 hole (by the looks of it) which, in theory, should give plenty of air volume to a 230mm inner. Will upload a picture later..

But for some reason when going from a 130mm inner to a 230 I lost 0.2J ?