Maximum fps

[NonEx]

Let me settle this once and for all.

 

For maximum FPS, chrono with .12g BBs

[Guges Mk3]

Hey Guges, I meant no disrespect. I was 1 in 1982 LOL. Quick question about the ice pick, if it's so good why don't marui or any other gbb manufacturer use a similar design?

 

Depends on who you seek for the part and the need.  Stark has their own variant as well as Azimuth.

 

TM has no need for it because their market requirements of ASGK.  Their valves already perform in the power range that they need.

 

The major underlying factor why people don't use it for the reason of this thread is that it limits high FPS.  This valve is focused on low temp operation.  

 

So, when its 9C out and you are hoping that your gun cycles and spews out the whole mag of bbs at ~275 fps, slide locks and doesn't vent, that's a good thing. Though the max fps at this operating range is going to be about 320 fps with a 7" barrel and you are shooting a .23g bb (max I could ever achieve with an IPV in sub 12C temps).  The threshold to shut off with the gas is so low with this valve.  It is not a device for high FPS GBB shots, unless you want it at 10C...then a conventional valve would never work this well.

 

 

Let me settle this once and for all.

 

For maximum FPS, chrono with .12g BBs

 

You have much to learn NonEX about details.  You must use .12g bbs, with hop-up off and shooting straight down off the side of a cliff.  

[Dimitri MdP]

If hammer springs do not account for any FPS gain?  Why do the even make them?  Why do they even work?  Why?  Because it release more gas Before the flute valve shuts and sends the slide back to reset the knocker.

 

well, at least 50% of airsoft "upgrades" out there have no reason for existing at all, and some are even detrimental. Specially when it comes to GBBR

 

But considering everything works OK in your gun (i.e. your OEM hammer spring has enough force to defeat the valve spring + gas pressure and completely open the valve in a reasonable speed) a stronger hammer spring does not make any difference at all. 

 

The reason stronger hammer springs exists is to allow "134A guns" to run on higher pressure gases, as they might not be able to defeat gas pressure and fully open the valve and engage the valve locker otherwise. Believe me, I've seen quite a lot of broken valve lockers, and the results are pretty much the same as what happens when you run a 134a gun on propane without upgrading the spring: awful gas efficiency, venting, poor recoil, etc

 

But for regular, "green gas" GBB guns they won't make any difference.

 

 

Have you ever seen an Ice Pick Valve?  

I own all 3 versions of those. To me it's just a sort of high flow, low pressure floating valve. Closes faster, but also allows the same / slightly more volume through.

 

To be honest I've not seen a significant difference for most cases, and in some guns (such as the Makarov) the OEM valve performed far better, as the "ice pick" provided a 10% decrease in FPS, which was already low to begin with.. Shooting 220 w/.20s (despite actually using .25/.30s) was low enough that almost no one would call their hits, which makes it really frustrating.

 

 

As for the video, 50ºF/ 10ºC is far below the ideal for working range for propane, but it still has about 77PSI. 7 slow shots is definitely not enough to get the gas cold enough for the gun to fail. Any gun will do that. Any.

 

 

That's the marketing trick we see here time and time again: video "proofs" that shows how cool a product is, by making some gimmicky trick.... that the gun was always able to do in the first place. 

 

 

-----------

 

Gas venting is caused when the pressure is not enough to cycle the gun, therefore the valve locker keeps the valve locked (duh) opened, and sends the gun in a cycle of colder and colder gas with lower and lower pressure, trying to fight atmospheric pressure + the slide weight + the recoil spring tension, which renders it unable to do so until it runs out of gas. 

 

This issue can only be addressed by using a higher pressure gas for the given temperature, and making sure there are no leaks between the gas route and nozzle input, nozzle output and chamber, and nozzle to BBU / bolt carrier.  So gas efficiency will be much higher, preventing unnecessary temperature loss.

A floating valve can't change that fact.  

 

That's why I was surprised by your "operational sensitivity" statement. There's no way 15PSI not 20PSI (at whatever volume) be able to run anything, as that's barely above normal atmospheric pressure (14PSI). To run most GBBs you need at very least 50 PSI, and to run them efficiently about 90PSI.

[3vi1-D4n]

I 2nd Dimitri's observations and interpretations.  >50% of upgrades in airsoft is useless, more so for GBBs.

 

Ice pick valve is a speedier valve, with a comparatively lighter flute valve spring.  Most pistols I have installed in has had either no change or a decrease in FPS.  

 

As to Guges measure of efficiency.  BBs per mag is only a proxy measure of efficiency (its a practical measure but not a system measure), and by the fact that the icepick valve closes earlier due to a lighter spring, of course will increase that said efficiency, but not by much. 

 

The other factors to affect efficiency: Gas tank volume, gas route seal, recoil spring tension, bolt mass, friction within the system, valve disengagement timing point and recoil perceived (function of a number of factors).  

 

However, points to note:

 

- The amount of gas used to propel the BB is small compared to the amount required to move the bolt weight and the recoil spring.  Heavier the bolt mass, the more gas it uses, likewise with the heavier the recoil spring.  Lightening the recoil spring tension has the biggest effect on shots per mag.  A stock VFC G36K will shoot at 12*C, around 20 rounds per mag, but with 8 rungs cut off the recoil spring, shoots at a whopping 50 rounds per mag.

 

- The timing point which the valve locker disengages can have large effect on gas efficiency.  On a WE AK, the difference between 5mm shorter cut off, can add an extra 20 rounds per mag charge.

 

- Vapourisation from the nozzle occurs only after rapid fire, when the mag has been depleted of gaseous propellant and requires energy to convert liquid propellant to gas, thus dropping temperature. 

 

- Venting occurs when there is insufficient gas pressure, (as Dimitri explained with the valve timing lock), due to drop in gaseous propellant in tank, AND the drop in temperature within the magazine.

 

The better measure is how much weight the magazine loses per shot.  This would determine how much gas was used per shot.

[Dimitri MdP]

- The timing point which the valve locker disengages can have large effect on gas efficiency.  On a WE AK, the difference between 5mm shorter cut off, can add an extra 20 rounds per mag charge.

wait... how can you even modify that?

[Dimitri MdP]

- Vapourisation from the nozzle occurs only after rapid fire, when the mag has been depleted of gaseous propellant and requires energy to convert liquid propellant to gas, thus dropping temperature. 

Conversion of liquid into gas is constant and occurs on every shot. 

[renegadecow]

wait... how can you even modify that?

You grind down the knocker lock so it releases the knocker sooner.

[Dimitri MdP]

You grind down the knocker lock so it releases the knocker sooner.

fair enough... but that will also decrease the felt recoil

[renegadecow]

To a degree. I don't do it myself since it's always hot here but it's advisable to do for use in colder climates.