Thats the switch for the mag prime, there would have been a plate or something that sits in the track and pokes down behind the piston to act as the blowback, but that same plate is what the charging handle pulls on to press the mag prime switch, so if you’ve removed that plate completely there’s nothing to press the switch anymore to actively the priming.
You can grind off the tab that hits the piston to remove blowback without affecting the. Other functions but that’s a permanent fix.
now , i need a blowback plate , so what’s the compatible blowback plate for this thing ?
Couldn’t say what plate is used for that specific model, they’re kinda all different unfortunately.
The plate looks like sijun , will sijun fit this ? its an fjs m4 , fjs uses the same strategy as sijun according to akgelblaster , so atp i could maybe run sijun dust covers and sijun metal blowback in this thing , even the charging handles so similar
AKG would know more about those ones than me, I’d trust them if they say they’re compatible.
Charging handle are usually more specific to receivers rather than gearboxes.
You are going the wrong way about it. When you pull things like that apart always take pics on your phone as you pull bits apart.
Look at your original post Fjs m4 cqbr block 1 review
You have all the parts already and anything aftermarket will likely not fit. It is delicate to get the blow back installed. Why like I originally said we get rid of them as we do high volume and that trinketry does not hold up.
Look at the parts you hopefully have still and take better pictures and we will try help.
Something about the charging handle went bye bye, well it won’t work without that nor will it with any aftermarket one,
Recommend not cross manufacturers as they differ greatly. To save you money.
It may look the same, but is it? Have you mic’d it up?
We are not sure where you are heading, what was wrong with the OG blowback? You’ve got to be gentle with them and 2S only or they shit the bed.
Your M4 looks great. Inspired me to get out my Cyma M4 Sporter and fix the loose stock. Now thats done, ive had a few shots but then stopped and thought about the state of the gearbox lube.
I am loath to pull apart the box as I have never been able to reassemble one correctly. Is there an easy way to get some lube though to the teeth without a full disassembly?
No… not really.
It’s a good time to do your routine inspection of the gears, bearings, springs, etc anyway. Nothing lasts forever with these things, and a bit of preventitive maintenance goes a long way.
No guts, no glory… plenty of turorials on assembling a V2 box on Youtube. 
i am gentle with them , i do my best to do anything but , i wanted to do a custom gel blaster on this nylon gearbox , now i’ve decided to add a mosfet to fix that blowback problem , now i need mosfet recommendations , gun’s shell , receiver and any external thing + t-piece is going to get cnc machined in steel to match the real m4 aesthetics and a 100% volume rainbow cylinder and a new inner / outer barrel is going to get added ( edit : i will cnc also the nylon gearbox shell lol )
this is the blowback , its not that resolute ( my blowbacks completely broke , so i wanted to disable it to prevent further problems and then i screwed the mechanism up
Go on, @Maiphut
I dare ya. 
@Commando_Elitium it looks to me like you’re heading down the path of a completely custom build with parts that are 100% bespoke as they’re remade in different material to the original OEM parts.
Good luck to you if you can pull it off, and I’ll doff my hat to you if you do… and I’ve got a lifetime of toolmaking behind me.
One thing I do know is that we’re not going to be much help to you while the project is still at this concept stage. If you’re talking about the rather ambitious task of machining full metal components based on the original nylon parts, good luck, amigo.
I’m not saying you can’t do it… anything’s possible given access to the right machinery, but if I were you I’d have to ask myself “why” when the original parts are more than adequate to meet the requirements of the design brief.
I’m not sure how losing mag prime in an attempt to disable blowback requires remanufacture of parts in steel. 
well , thanks man but i don’t wanna do it a blowback again
Now i need a mosfet recommendation ( i will import some of it from china maybe ) and then I will make the thing
but the cnc will arrive next year , recently it got released from chinese customs clearance and will take time to come here ( a cnc expert from sweden is coming to iran to setup the thing , and that will take exactly 1 years or even less but my exams doesn’t let me the time it comes
well , if the cnc comes ( cause i want to get a job there and work , lmao ) i may mass produce this concept in a ultra realistic way but W/ SN Like SN0000001 or SN1038329 so i can ship it internationally and for export ( no larping but this is a 50% thing cause i’m producing them with mil-spec alloys like 4150 CMV that is used for real guns )
Have you done the courses to run a CNC Lathe 
, because I have and it it aint no weekend deal that is for sure.
Not having a go at you but you seem like you need to lower your aim a bit.
Aim for the stars, keep agl below the clouds. 
It’s something way beyond me because I am a maintence Fitter and Turner, welder, machinist for decades since I was a kid and what you are talking seems to me not achievable nor worth it for the end result.
Just trying to help you not go down a big rabbit hole and end up blowing money. It’s all good, by all means please reply. Apologies if I seem angry but I am not. Brightened my morning up that is for sure
He’s 15 @Maiphut @Friendly_Fire, still at school, no job etc.
Wasn’t very popular on the Akgelblaster Discord for all sorts of talks and claims, but everyone has to have dreams in life I suppose! 
Oh, okay.
Explains a lot then.
So what I started at 17, your point being?
No , but in the limited time that guy from sweden is coming (that cnc expert ) i’ma learn from him
also one day i’ve created a single shot bolt action shotgun primer & ball firing weapon with a music stand and a trigger and other things that i’ve made for it ( no larp , this is true and that thing nearly exploded )
i saw an m16a4 build based on this fjs m4 but the metal gearbox version , the outer shell got all cnc-ed ( on reddit )
now , i am going to build ANYTHING IT HAS from the gearbox shell , to the outer body
my age never says anything coz when i was 13 , i got a disposable , non blowback gel blaster and converted it to blowback ( https://www.youtube.com/shorts/-xHrVzwBrIE )
i want to work , coz thats the only thing i can do to buy more gel blasters ( my own income ) these gel blasters were bought with trading money , the money i did get from forex
and that was just 270 bucks for both bohan slr / fjs m4a1 v2 jinbo edition
idk if its a cnc lathe / laser cut or waterjet machine or anything like that , but i know it can machine these type of steels and cut them and make them in the way it should , easily
i saw how ghost gunner machines make real receivers for ar-15s , i saw the manufacturers used cnc to build these things , so i got inspired and can’t wait for that thing to come
i want to build a great gel blaster , cuz money isn’t the priority for me , the only thing is QUALITY , QUALITY , QUALITY
i’m not also angry , you know my english may suck and i do an apology for it , but here’s the point : i will machine the thing when the machine comes , now its just a fully dissasembled gun on 2 plastic bags named upper ( for upper reciever ) and lower ( for lower reciever )
It’sl all ok mate. This is how Australians are.
I just thought you were a little ambitious. Nothing wrong with that go for it by all means.
Was just thinking a lil costly. But you go for it mate. Seriously get into it like I did. 
17? You were a late bloomer mate!
My sister and I started at 14 and my Daughter was out of home and into the workforce at 15!
Pulling the piss as you know mate, but at least we had enough maturity and understanding of the real world not to bang on about such unrealistic “goals”.
Well I had to finish year 12 the ARMY told me 
