HPA magwell adaptors

[davidf]

Hi all. Getting tired of how sluggish my GBBs have been the last 2 gamedays due to how cold it is at the moment. 

 

Browsing websites like Airtac, but, not sure what magwell adaptors I need for the following items. Hopefully, if I share a list of rifles I am looking to get adaptors for, you can help me with some direct links

 

So here goes;

VFC A+ N4 Noveske GBB
VFC SR25 ECC  GBB
Krytac Kriss Vector GBB

 

Thank you!

[ButcherBill]

Have you tried Co2 mags? I believe they work better in the cold & you might not fall into the HPA 'dream'

[RostokMcSpoons]

I bought an Airtac adapter, and with a simple twist of the regulator knob on the air tank, I made something inside my beloved VFC HK416 perform a Rapid Unscheduled Disassembly.   It went from 'sluggish' to 'busted' with one ill-judged moment.  A bit of metal broke off, not sure if it's from the bolt carrier or the trigger assembly, but the whole thing is jammed together and I've not been able to separate the upper from lower receiver (though I've not tried very hard yet).

So what ever you do, take note of my hard won words of wisdom / caution:

1.  Ensure your RIF is well lubed and shooting nicely at room temp from gas, so there's no internal stickiness to overcome.

2. Dial the air pressure in slowly (starting at 'way too low'), in small increments.  

The adapter will add a lot to the effective length of the mag well, so maybe invest in some VN mags for AR's, or short MP5 mags, as appropriate?

Edited January 27 by RostokMcSpoons

[The_Lord_Poncho]

1 hour ago, RostokMcSpoons said:

2. Dial the air pressure in slowly (starting at 'way too low'), in small increments. 

 

I'm not sure it 100% translates to this situation, but I read somewhere that at room temperature, normal green gas is around 120-130PSI. So on any GBB running on an HPA adapter, I treat this as the maximum PSI that i am prepared to go to without putting undue stress on the internals.

[davidf]

Thanks all. I did consider co2 and it starts strong but in 1 degree C night games it slugger later.
Will be very careful starting 70psi moving slowly to 100/110ish to make sure its all good

Thanks all!

 

I think this is the one I need for my n4
https://airtac.me/products/vfc-apfg-m4-hpa-adapter-modular?variant=48572369010979

 

[davidf]

2 hours ago, The_Lord_Poncho said:

 

I'm not sure it 100% translates to this situation, but I read somewhere that at room temperature, normal green gas is around 120-130PSI. So on any GBB running on an HPA adapter, I treat this as the maximum PSI that i am prepared to go to without putting undue stress on the internals.

 

What's the best way to balance npas and psi? 

 

Would you open the npas all the way and the  manage the psi. Or utilise both?

[Chev Chelios]

6 minutes ago, davidf said:

 

What's the best way to balance npas and psi? 

 

Would you open the npas all the way and the  manage the psi. Or utilise both?

 

The less propellant you have to use to send the BB down the barrel the more that can be utilised to push the action rearward.

[davidf]

And I can use any branded AEG m4 mags. So I could get a 5x pack of specna arms aeg mid caps and that would just work in the VFC hpa mag adaptor?

Edited January 27 by davidf

[GiantKiwi]

1 hour ago, davidf said:

And I can use any branded AEG m4 mags. So I could get a 5x pack of specna arms aeg mid caps and that would just work in the VFC hpa mag adaptor?

 

Airtac adapters need to use AEG mags with a significantly higher spring strength, cheap AEG mags are almost always not up to snuff. PTSEPM1/1S definitely work (what the adapters are designed around), older EPM's (Gen1) do not. Mags i've tested that do not work, anything made by KWA, Specna, Ares, Classic Army. Some CYMA's can work, but only more modern ones, G&G are hit and miss - if they have the follower that goes outside of the mag lip, forget it, G&P Troy mags will work, but you'll have to part fill.

 

PSI wise, it'll depend solely on if the adapter in question has a built in expansion chamber, if it does you will be able to run it on 80-100PSI. If it feeds the line through the adapter direct to the output valve, it won't run on anything less than 120-130PSI, and probably more realistically 140-145psi (and if you've got heavy bolt, or other heavy recoil mods, higher PSI to overcome mass).

 

Edit: Looked at them. Neither variant of airtac for VFC M4 has an expansion chamber, so its higher PSI almost certainly.

Edited January 27 by GiantKiwi

[Barny]

I'm not sure if i'm going to be much help here... Very new to GBBR, and not exactly a whizz with hpa either!  

 

This is an APFG MCX Spear, which i believe is based/made by VFC.

Its got the Airtac VFC adapter in it with a PTS short 170rnd mag.

 

Plays nicely at 120psi on the regulator which is handy as my DMR's are set to that too. The npas was removed as it fell out whilst tinkering and i've not bothered to put it back in yet. Ive since fitted the winter springs as recommended on this forum but i appear to be getting bolt bounce so may swap these out and/or refit the npas. 

 

I've not used it in game yet so ive no idea how it will perform. Thinking of spraying the adapter tan to blend it in a bit too 

[GiantKiwi]

13 hours ago, Barny said:

I'm not sure if i'm going to be much help here... Very new to GBBR, and not exactly a whizz with hpa either!  

 

This is an APFG MCX Spear, which i believe is based/made by VFC.

Its got the Airtac VFC adapter in it with a PTS short 170rnd mag.

 

Plays nicely at 120psi on the regulator which is handy as my DMR's are set to that too. The npas was removed as it fell out whilst tinkering and i've not bothered to put it back in yet. Ive since fitted the winter springs as recommended on this forum but i appear to be getting bolt bounce so may swap these out and/or refit the npas. 

 

I've not used it in game yet so ive no idea how it will perform. Thinking of spraying the adapter tan to blend it in a bit too 

 

Did you shorten said winter springs to 230mm?

[Barny]

10 hours ago, GiantKiwi said:

 

Did you shorten said winter springs to 230mm?

 

No, i just swapped 'em straight in. Assumed the softer rate would offset against the longer 300mm length. I'm guessing i should?  

[GiantKiwi]

17 hours ago, Barny said:

 

No, i just swapped 'em straight in. Assumed the softer rate would offset against the longer 300mm length. I'm guessing i should?  

 

Recommended on HRC is to make them 230mm long, to stop misfeeds - which is typically caused by bolt bounce.

[jlb]

Recently ordered the ghk airtac valve for my vipertech m4 so hoping it works well. Ran it on C02 magazines all last year but in anything other than warm weather fps drops off quickly with long bursts of FA being out of the question. With higher pressure gas or hpa it runs flawless. Also ordered some epm1 s mags..

 

The only issue i had all season was several misfeeds during one game after reloading some spent 40rnd mags without renewing the co2 bulbs causing the action to slow down too much. Been fine ever since..

Edited February 4 by jlb

[Titchiemagoo]

Just a out of the box idea but I've seen heated pouches, they charge via USB and keep the pouch at a specific temperature so theoretically you could keep your green gas mags in them till you need to reload, how it would work in the real word I don't know, just throwing it out there.

[The_Lord_Poncho]

1 hour ago, Titchiemagoo said:

Just a out of the box idea but I've seen heated pouches, they charge via USB and keep the pouch at a specific temperature so theoretically you could keep your green gas mags in them till you need to reload, how it would work in the real word I don't know, just throwing it out there.

Those activated charcoal hand warmers work too - as a low tech alternative option.

[jlb]

Sounds worth a try, surprising what difference a small temperature change can make.

[Titchiemagoo]

On 07/02/2025 at 20:49, The_Lord_Poncho said:

Those activated charcoal hand warmers work too - as a low tech alternative option.

Yer those work to although you'd have to keep buying them, the others you just charge via USB.

[jlb]

Got the Airtac valve running on the vipertech, luckily i also got the mancraft mmr secondary reg as it runs at 200 psi. Will soon find out if a 48ci bottle is enough or need to get a bigger tank..

[jlb]

Had a good outing on Sunday, the 48ci tank is enough to empty several 170 rnd pts mags & did not go much below 2000 psi in any of the games. Used vorsk bio bb's as they were the only ones i could get in time, no misfeeds or other issues also used plenty FA. Def sticking with hpa only from now on.