Airsoft Gas Blowback 101- How Does a GBB Work?

A brief overview of the operating mechanism used in virtually all modern gas blowback airsoft pistols and rifles.
Magazine Maintenance Guide:
• Airsoft Green Gas Maga...
Gas Blowback Maintenance Guide:
• Airsoft Gas Blowback M...
Music by Karl Casey @ White Bat Audio

[@lidith2786]

Gas goes in, bb comes out... Gotcha!

[@tylerblalack6684]

Nice FAL

[@culan_SCP]

i prefer dryfire :)

[@RotaryMarx]

Knife goes in, guts come out.

[@ProPainAirsoft1]

As somebody who has personally directly asked you questions on the Heavy Recoil Club Discord (and had them answered swiftly and gracefully), and who frequently revisits your videos for the countless valuable bits of information, I'd like to thank you for your selfless hard work and contributions to the community. We ALL appreciate it.

[@millo7295]

Selfless? He gets paid to do this, breh

[@gaveintothedarkness]

This is a great detailed explanation of the GBB system. When I was first starting out, it took me hours to figure out the inner workings and how all the different elements meshed together.

[@RedVRCC]

A lot of GBBs function nearly identically to their real steel counterparts with the exception of the propellant source. If you take apart a GBB pistol, you'll notice a striking parts commonality with the real thing. In fact, I was rather astounded myself when I took apart both my real Glock 17 and airsoft Glock 18 and noticed how many parts are similar. Sear, trigger, recoil spring, etc are all nearly identical. The main differences are a nozzle instead of a firing pin and the gas source itself coming out of the mag. Some of them were so similar I had to make sure I didn't mix up the parts and put the wrong part into the wrong gun.

[@YoChocolate]

Very well explained, better than a 3D-animation could do! Common issue with gas blowbacks is liquid gas visibly spewing out the side or even the muzzle during fast shooting or full-auto. If you could cover this in the next video it would be appreciated.

[@ExplosiveEnterprises]

Thanks, and we'll definitely be covering siphoning in the next video.

[@Guido_XL]

My Umarex Walther PPQ seems to do that more often than my Cybergun/WE and Tokyo Marui Deagles, if I do not use it for some time. I got the impression that the output valve is the culprit, when the valve's mechanism becomes compromised during fast repetitive shooting. I noticed with one of the mags that belong to my TM Deagle, that it doesn't close properly anymore, so that when I try to refill it, the gas immediately escapes from the gas router. When I removed the valve, I noticed that it did not open and close smoothly anymore, as the axle seems to be bent a bit. But this mag has functioned well before, so how did it sustain such a damage? Anyway, I've got enough mags to spare, and valves can be replaced, but still, this is something that bothers me a bit.

[@imma5028]

Love the analytical content. Could you guys do a deep dive into airsoft 40 mm shells and practical uses with focus on fielding, holding in pouch without having bb’s fall and uses for the variety of shell types?

[@ExplosiveEnterprises]

No guarantees about when we'll have content up, but it's on our list.

[@imma5028]

Alright, thanks for letting me know!

[@user-ws3eo5pl7v]

@@ExplosiveEnterprisesHey man hoping you could answer one of my questions. At part 6:30 how does the loading nozzle get yanked like that I don’t understand how it functions.

[@EuthanasiaSUPREME]

Best airsoft YT channel. I always wondered why there wasn't an airsoft channel that covered topics in depth and from multiple angles such as STEM related concepts, history of real firearms, and competent experience based tech info. All these videos are concise and informative, while being entertaining to watch and easy to digest. Great job mate, the hobby needs more of this tier of content.

[@arcticfox7.62]

You guys are the best of the best. For people like me that are trying to get into airsoft in general, the content you make is a goldmine

[@Gojira_Wins]

The amount of times I've had to link your videos to people who were arguing with me over simple stuff like this and why Superlube is the best lubrication to use for GBBR, is honestly astonishing. Hopefully this video will educate more people on how these guns work. Maybe there will be fewer people arguing stupid points like how "AEGs are better because GBB Guns have more moving parts". Yeah, 30 parts vs like 3 or 4 in a gas gun. Would take a paragraph to explain an AEG while GBB is gas, boom, boing, ready lol.

[@botodin6979]

As a noob, I am VERY appreciative for this!

[@L1f3665]

I never thought that I would’ve found this interesting to learn about, I was wrong. Thank you for the video 😊

[@WolfMan-nf4lv]

Awesome video as always, guys. When you really boil it down, gas blowbacks are pretty easy to understand once you become familiar with them. And personally it didn’t take me long at all to get a good idea of the workings of these guns. They’re so much simpler than people give them credit for

[@Guido_XL]

Yes, well, once you get started with maintaining and upgrading AEG guns, things can become more daunting, as you have to deal with fiddly mechanical and electrical issues that need to interact flawlessly. My only experience with GBB is with my Deagles and my Walther PPQ. I only have AEG rifles, no GBBR ones, so that I came to learn the intricacies of gearboxes and mosfets, triggers, and nozzle/hopup tweaking, even before I operated upon one of my Deagles to repair the valve-knocker. I actually replaced the original trigger-spring in another Deagle of mine with a spring from one of my wife's hair clamps! It was a perfect match, and from hindsight, that hair-clamp spring does a better job than the original trigger-spring from the manufacturer. This is definitely a sport for tinkers and techno-geeks, apart from the odd skirm opportunity that comes along.

[@formerlyeyes]

Always a good day when a new EE video drops 🖤 thank you for all that you do

[@sevensixtwobyfiftyon]

Thanks for not wasting the first 2 minutes telling me to like and subscribe and how totally awesome you are. I did like, probably won’t subscribe and there’s a good chance I will buy from you because of the high density of well explained information in your video.

[@Votler1]

It always makes my day when I see that you've posted a new video!

[@nefas11]

Yeah new vid!,,

[@noname-rv7yh]

subbed - as someone coming from real firearms to airsoft - for training and trigger time i appreciate the heck out of these videos and ur channel!

[@Hobbnob_FirstPersonAirsoft]

Another excellent video, solid stuff Cat and nice work especially getting such clear images of the smaller components If I may make a suggestion for your myths and misconceptions video, I've seen people parroting that the nozzle sticking in the bucking when pulling back manually is a sign of good gas seal, and vice versa if it stops sticking. I personally have no idea whether there's any truth to this beyond the physics of gas potentially leaking between the bb and the gap between the bucking/nozzle if the gap is really that big, but it would be good to see some more input on what it means when it sticks, what it means when it doesn't, and what it means when it changes day to day.

[@ExplosiveEnterprises]

Already in the script- that's a fun topic and definitely one we plan to address. No point in keeping it a mystery, though, so tl;dr: It doesn't really mean anything whether the nozzle sticks or not, because a good seal may not stick at all, and a bad one caused by a pinched bucking may snag on the nozzle and make it stick. The best way to test your seal is simply to check whether it seals.

[@Hobbnob_FirstPersonAirsoft]

@@ExplosiveEnterprises fantastic great to hear it, and good point on the pinched bucking type of issue too

[@Oper8or]

This is an excellent video and instruction guide for new people looking to find out how the system works. In all fairness I am an armorer and have a firm knowledge in how firearms work but the gas blowback system is something that struck my curiosity and I wanted more information on it. Diagrams are nice but I am a hands on person and learn more by doing then reading. Now I just need to figure out what gas to use, type of airsoft gun to use, and what spring tensions are used for the parts to see if they can be tuned for multiple pressure levels or if the system requires a static pressure until empty.

[@guillotine_airsoft]

Awesome video!

[@riosaswin6580]

Tried to understand everything you explained. But it was so much info i got lost after 30 sec. But it was definitely interesting 😅

[@wr3nche5]

wow... it amazes me just how realistic GBBs are

[@rawr2u190]

Interesting. Thank you, this gives me ideas for increasing felt recoil.

[@PydracorsForgottenAirsoft]

Highly informative and to the point (as all of your videos are :)), a must-see for people new to the hobby and still interesting to watch for more experienced airsofters - thanks a lot, really cool!

[@SickkntTactical]

wow i never knew you could bottom fill glock mags lol super helpful

[@RedVRCC]

I wish GBBs were more common. There's so many guns I wish had a GBB version and I would definitely pick them up if they were available. I'd absolutely love a GBB AK-12 to go with my PP-2000 and MP-443 Grach for a complete, immersive Russian loadout.

[@JunPT266]

Excellent video as always. 👏

[@schtinerbock4570]

New favorite channel.

[@foxgamer1793]

FUCK YEAH

[@GoGreenMan]

Very well done technical videos, keep it up!

[@AlexandreParchomenko]

Great vid ! Very instructive content, I learned a lot today !

[@heitorvieirafilho2643]

Great explanation

[@hdbfu0214]

Can you make a video to explain how a Glock pistol works please❤❤

[@davidstandish4767]

In other words, gbb guns are equally if not more complicated then their real counterparts. Pretty interesting stuff

[@MikeHuntsPews]

God dam that is a good video. I have tried to explain just this to people before, I can now just send them your way to this video. I tell them your like Eminem of gas guns, “gas gun god”

[@savedchannelfullgospel7442]

Very informative!

[@mrfischinnsbruck]

Great video thank you!

[@RazorNLD]

Also, I would like to know exactly in which part the NPAS comes into play? @10:52

[@Zadren]

Great vid, thanks 👍

[@flyingairedale]

At 7:04 this video shows a BB being driven into the chamber as the slide returns. I assume this means that once the trigger resets, the gun can discharge another BB. I discovered that my rotary magazine Sig P 226 does not rotate another pellet into place until the trigger is pulled from full forward. I had been baffled by gas being discharged without a pellet for years until I started removing the mag after each discharge and noting the position of empty positions in the mag. I was told by Pyramid Air and Airsoft Depot support personnel that all airguns had to have their triggers returned to full forward in order to discharge another round. This video seems to indicate that the illustrated pistol can discharge another projectile as soon as the trigger resets. Is that correct?

[@RazorNLD]

That TM AK Kit, where did you get that handguard, barrel and iron sights from? It looks like a galil?

[@Phyxius_Debello]

I got a few questions, I hope you can answer. I'm planning on getting the umarex/VFC HK416 A5 gen 3 GBB. It would seem some mags v2 dont work as well as the current V3 gas delivery system. Would putting regular propane instead of the green gas cause any problems? Your video seems to suggest not to use green gas at all. Also, I'm trying to research if any M4 style GBB mags would work for this gun or it needs to be a Vmag?

[@bpeyman68]

How would open bolt guns work

[@find-me-at-Clumslay]

I have a problem with my SVD Aim top rifle that it does not cycle at all anymore and only vents all the gas out until I pull the bolt back manually. I haven’t used it or touched it for a whole winter and now just started back up on maintenance. My guess is that the rocket valve is getting stuck inside the nozzle because it hasn’t been lubed for a _long_ time. So if I lube it with silicone oil, it should work again, right? Or do I have to buy a spare nozzle to replace it? I wonder if anyone else encountered this problem as well. I’ll update if the problem is fixed. Otherwise I’m open to suggestions. PS don’t buy an AIM Top gbb rifle, they’re too much.

[@patrickmuller5223]

Doas the nosse go outside pf the piston head or is the piston head stol coverd/sealed inside the nossle when it is the MOST extendet

[@oscarfirenandez6875]

perfect 1:16 how many takes did that take?

[@tobyc8905]

Do you need to use propane with silicone oil in it or can you use straight propane?

[@ThomasB634]

What m4 is that with that super realistic trigger group?

[@sogerc1]

Question: what difference does it make how stiff the nozzle spring is? I've heard people say that for ex. they'd put a 150% nozzle return spring in their gun. But AFAICT the nozzle doesn't need to go back into the carrier, it only needs to go back behind the next BB and there is a stopper on the carrier which yanks out the nozzle from the hopup anyway. The GHK AK doesn't even have a nozzle spring and it still works fine. Bonus question: where does this Desert Eagle + huge red dot combo come from? I've seen something similar on facebook once and I liked it so much that I had to get a big red dot for my own Desert Eagle.

[@ExplosiveEnterprises]

While the nozzle should clear the BB stack even if it doesn't retract at all, the timing is often fairly tight, and it's possible for the carrier to cycle so quickly that the next BB in the stack doesn't have time to pop up before the nozzle goes forwards again. This can also be an issue if the gun siphons liquid propellant (something we'll cover more in the next video), which takes time to expand in the nozzle and can prevent it from collapsing at all. Plus on some guns, the nozzle may retract far enough to exit the hop, but not far enough to clear the BB stack without some help. In any case, a stronger return spring /may/ help the nozzle to retract and lengthen the amount of time before the BB has to be presented for feeding, but more often than not it isn't actually necessary. Otherwise, the main issue we've run into with spring-less systems like the GHK AK (or KWA MP9s after they yeet their return springs) is that if the nozzle doesn't retract at all (typically due to friction), it can actually feed a BB into the chamber and /then/ collapse into the carrier, and the only way for the trapped air inside it to escape is out the front- dislodging the BB or potentially even ejecting it out the barrel entirely. GHK gets around this by making the feed lips excessively tight so that the nozzle cannot strip the BB until it collapses into the carrier, which is, well, one way to solve it. As for the Desert Eagle, our owner was inspired by both Predator 2 and Marathon 2. It doesn't do anything a modern micro dot can't, but it sure looks cool.

[@sogerc1]

@@ExplosiveEnterprises Thanks for the info, fortunately I haven't run into this issue yet. About the Desert Eagle, I'm a big Predator fan, I suppose the image was just sitting deep inside my brain. It was the same deal with the KTW Spas-12, I had to buy it because for some reason I found it very cool even though it didn't have the iconic folding stock, and then years later I rewatched "The Matrix" and understood why.

[@agitatedtofu2511]

I am looking to get more into gbbrs , but have been getting mixed advice with propane vs green gas, does propane actually go through seals and need to have silicone grease added and or seal manually maintained, or is it not that big of an issue

[@624635Mr]

Any plans to do one of your in depth reviews on the VFC M4 platform? Specifically the gen 3 such as the HK416, URGI, BCM, SR-16

[@pyroromancer]

looking forward to 102

[@GaosenKinetics]

What are all these words help me I'm scared

[@Trzebiat]

I've been always wondering what will happen if you fire a gas blowback pistol if the slide is locked so it can't go back? Basically can you turn a GBB pistol into a Hush Puppy by mounting a slide lock mechanism so after the shot you'd need to deactivate slide lock and manually rack the slide before another shot? Or the gas pressure would cause damage to the nozzle, rocket valve or something else and a single shot would release all the gas from the magazine?

[@YoChocolate]

In theory this would just cause the nozzle to hold the pressure of the mag after the rocket valve is closed. If everything is properly sealed, no more gas would be released until you let the slide go, then the pressure pushes the piston back and the gun cycles one time like usual.

[@ExplosiveEnterprises]

Because the valve knocker holds the valve open, preventing the slide from cycling causes the gun to immediately dump all its gas through whatever seals are imperfect. You can, however, get the desired effect by removing the rocket valve entirely (so the nozzle cannot seal and build pressure- all the gas goes out the barrel) and changing the hammer system to a rebounding type as on NBBs (so it strikes to release a certain amount of gas, but doesn't lock forwards). But these are permanent or at least not field-adjustable modifications, so it isn't possible to get a selectable Hush Puppy this way.

[@Trzebiat]

@@ExplosiveEnterprises that's what I thought. Would be interesting if it would be possible to make a Hush Puppy and be able to switch between semi auto and single shot with slide lock. Maybe if there would be some kind of secondary rocket valve that would be connected to the slide lock which would unlock it when the slide is locked so it would cause the valve knocker to reset. In theory that could work, technically the separate reciprocating part of slide that engages the reset that is either unlocked from the rest of the slide and reciprocates to reset just the valve knocker if the slide lock is engaged, or it's locked with the rest of the slide when the slide lock is disengaged so the whole slide cycles. Sounds complicated though. Btw, are there any NBB pistols that have the slide that you can rack to arm the hammer and go from Double to Single Action? Except TM Mk23.

[@cayancesardeoliveira5708]

Great video! Let me ask you a question... What happen if i put a stiffer spring on the nozzle (or a stiffer o-ring in the nozzle) to make the nozzle travels back faster with the bolt/slider ? Greetings from Brazil!

[@MargiAirsoft]

Thank you for, once again, the great content. I'm a fellow HRC member and while I sometimes get the itch to be done completely with AEGs, I still can't bring myself to actually do it. Do you guys still own some and if so, do you plan on covering them the way you do with GBBs ? Keep up the excellent work 👍🏻

[@ExplosiveEnterprises]

Most of our members primarily use AEGs, actually. We just find there's usually less to talk about, since the gearbox-in-a-shell nature of most AEGs means they tend to be more similar to one another and less constrained in what can be done with them. Plus, AEGs are better covered by the KZbin community already- we started making reviews of GBBs because we were disappointed with the lack of quality content.

[@MargiAirsoft]

@@ExplosiveEnterprises Understood. Looking forward to the next quality content you'll put out 💪🏻

[@jamesterry1341]

excellent video, explained really clearly! I was wondering have u have switched to using vfc m4 mags for ur vt replicas ?

[@ExplosiveEnterprises]

We have- we suggest you check out our prior videos on the platform (Building A Better Viper Tech) for more details. Long story short, VFC AR mags are seriously ahead of the curve in pretty much every way except physical appearance.

[@jamesterry1341]

@@ExplosiveEnterprises i shall check that out, as well i guess u can actually find them pretty regularly without the need to sell organs to pay

[@kakuwave]

I don't think the flow valve gets pushed and seals, if you stop a gbbp from cycling you can clearly see the gas all spewing from the barrel The cycling is due to the fact that the gas goes both towards the barrel and the back at the same time, and trying to expand at the back makes the gun cycle

[@ExplosiveEnterprises]

When the slide is held, the gas escapes through the barrel because the typically plastic-on-plastic contact of the rocket valve against the nozzle does not seal as effectively as any of the nitrile rubber gaskets used elsewhere, so it takes the path of least resistance. In normal operation the seal is sufficient to minimize losses- if you modify the gun in such a way that the rocket valve cannot fully seal, it will (usually) still cycle, but there are direct and noticeable effects on blowback and efficiency. We'll be covering this in the next video.

[@CLODXJ6]

If what you're saying was true at all then that would mean the nozzle valve could be removed without issue. But clearly that isn't the case.

[@opairsoft8100]

Average airsofter moment be like:

[@kakuwave]

​@@CLODXJ6i have yet to test it. I heard once about a gbbP cycling even without the rocket valve tho

[@kakuwave]

​@@ExplosiveEnterprisesthank you for tbe explanation, I'll look forward to the dedicated video, keep up the good work! Also hurry up and get a vfc scar H, I want to see what you'll come up with to make it more reliable!

[@Captain_Coleslaw]

Should i store my airsoft guns with a mag in or not, and should the hammer be cocked or and on safe, or should it be on semi and dropped?

[@orangecube3445]

Store without a mag, the hammer shouldnt be cocked.

[@Nyasiu]

That's a lovely Glock Gen 2! What brand is it?

[@ExplosiveEnterprises]

WE for the donor internals, Guarder for the frame, PGC/Prowin for the slide, and Maple Leaf hop parts.

[@SHKUDOY]

vipertech with dna mag?¿?¿?¿

[@sogerc1]

How do you lubricate the nozzle o-ring? Do you remove the nozzle every time? Because that's more disassembly than I'd like to do during maintenance.

[@ExplosiveEnterprises]

We suggest checking out our gas blowback maintenance video- basically, you can just drip oil in without disassembly, or if you disassemble once to grease the o-ring/piston then you will rarely need to do it again.

[@sogerc1]

@@ExplosiveEnterprises Thanks, I think that video was released shortly before I found your channel.

[@johnescobar1520]

Sir can i lube the nozzle or not?

[@khanmike6858]

absolutely not

[@aeebeecee3737]

Yeah, but how shell ejecting GBB works? And who want to know too?

[@MK384]

What brand is your Car 15 clone and what clamp do you use to mount the flashlight?

[@ExplosiveEnterprises]

It's a Viper Tech replica of a Colt 727, and you can see more of it in our prior videos on the platform. The mount is a generic Chinesium clamp-on rail section and a Weaver ring to hold the light body.

[@MK384]

@@ExplosiveEnterprises thanks for the response. Where do you source the Viper tech 727, is this something I can still buy or is this an older replica? Also where do you all buy your GBB's since you seem to have a very nice supply of GBB items.

[@ExplosiveEnterprises]

​@@MK384 Viper Tech replicas are best sourced directly from the manufacturer. They still make all their models to order, as far as we're aware. As for other GBBs, we get them from a variety of predominantly Hong Kong and Taiwan based retailers. WGC, Redwolf, Proact, Airsoft Global, and eHobbyAsia have all been reliable for us.

[@yangsenzini5704]

I though all of this time it also use battery 😢

[@Lostandfoundbinwow]

Actually dark magic lmao

[@jakobmax3299]

When you realise that gas blowback airsoft guns are actually far more complex than real guns...

[@OhFuckYouAlready]

Which Makarov do you have in the starting of this video? Would you recommend it? Any tips and tricks?

[@ExplosiveEnterprises]

It's a WE, and while it's the least bad airsoft Makarov that is unfortunately a very low bar. The barrel and slide have enough unavoidable slop that the sights are more or less useless, the hop-up is fragile and cannot hop above ~.25g without modification, it's very typically WE in its pot metal construction and ensuing wear, and since it was actually patterned off a Baikal airgun actual Makarov grips need extensive modification to fit. Unfortunately, our best tip and trick is to avoid it altogether.

[@mountainadventures7346]

Hey! Thank you for what you guys do! Gas enthusiasts everywhere I am sure feel the same way I do!🇺🇸🫡