Wanna try making a AA12 shotgun

[Meathead316]

Hi

I wanna try my luck at making a AA12 AEG shotgun.

From a quick google search I have found that this has been attempted in the past, but no one has ever finished it....

Now I'm gonna be realistic, this is not going to be easy, and after ive got the basic components and had a tinker, I may well find that its just not feesable for 1 guy to do with basic materials and simple tools and parts, but we will see...

Basically what I want to make is take the Tri-shot effect from a spring shotgun and combine it with the full auto awesomeness of an AEG.

What I WONT be doing:

- Modding a sandard gearbox to triple feed (as if it misfeeds and only feeds 1bb, it will fire super hot!
- Using shells of any kind (shells are cool, but I want a skirmishable weapon)
- Pouring 100's and 100's of hard earned dollar ino this (think I am? made of money?!)
- Making it 110% bang on real life accurate (some aspects may have to be altered slightly to make it work, as i did with my minigun)

My plan is:

- M4/M16 AEG (metal gearbox is a must) cut it down so that its just the lower half of the body, gearbox, trigger and grip. This will then be rear wired. Internally i will be upgraded with torque motor, torque gears, reinforced piston, 400-500fps spring

- Hicap mag, most likely an M14 mag as they are straight

- 8.4v battery (I dont want the rate of fire to be too high, say 10rps max)

- 3 barrels each with its own non adjustable hop (similar to the tri-shot shotties)

- a feed system which will be some sort of AEG/Tri-shot hybrid.

- A scratch built PVC AA-12 body which must come apart to allow access to the internals and have space for a battery in the stock.

So far I have found LOTS of referece pics, and have made a simple cardboard cut out of the gun. My first thought was "its massive" but i double checked and all measurements are correct. This is good as it give me more space iside to fit everything

Also I have laid my M4 (which I am most certanly NOT cutting up for this project as it was the first AEG i ever bought) ontop of my cut out and the grip, magwell, trigger and barrel all line up!! :D

So far so good, but what I need now is help. Not with my build plans (unless you see major flaws in my ideas.....) but with parts. I for 1 have loads of guns, and a few boxes of "airsoft stuff" one is full of mags, shells, carry handles etc etc, the other is full of random internals, but, most are broken or not suitable. Now I cant be the only one who has a random box full of parts, so if you do then have a root around for me and buying brand new will cost loads more!

So before i can really begin I need to source parts, I need:

- M4/M16 AEG with a metal gearbox (any condition, and I only need parts mentioned above)
- 3 Identical inner barrels (or some sort of metal/plastic pipe with 6.04ish inner diameter, M4 barrel length)
- 3 identical nozzles
- High torque gear set
- High torque motor
- Reinforced pison and head

So if you have these parts you wanna sell (or donate!! :P) then reply here or drop me a PM!

As soon as I get these parts I can begin working on making the feed system, and if (and only if) that works will this project continue (surely it cant be that hard....)

[jonny lovegrove]

Re: Wanna try making a AA12 shotgun

as you want to use an m4 as a base, why not do a USAS? Wiki Page

[bob86]

Re: Wanna try making a AA12 shotgun

and why use such a powerful spring and high torque gears, why not build it first, then look at upgrading the parts once it is working?

[Jez Armstrong]

3 barrels, 1 AEG gearbox

Tell me how that fires?

[Coski]

Re: Wanna try making a AA12 shotgun

What if I you just made it 3 round burst with an extremely high ROF? Would fire so quick that it would mimick the effect of a tri shot, whilst making your job with the internals much easier...and cheaper.

[Figjam]

Re: Wanna try making a AA12 shotgun

I've been thinking about this myself quite seriously. I reckon you need to use the feed, pistons and cylinders from a tri-shot, and then while you are at it you might as well use the hop and barrels too.

Its going to be hacking the piston so it runs off the sector gear while still functioning in the triple cylinder/piston off the tri shot. Going to be a bit of a job putting that chimera together.

Job 2 will be fitting it into the GB housing. Perhaps use the lower part of an ICS split GB or similar and somehow fabricate the upper half yourself?

Have a look at some of the mods that use the shells as an adaptor so people have attached m4 hi caps to tri shots... change this to a drum mag and you are on to a winner!

Internally I reckon its a little bit of creativity and a good amount of engineering. Externally is where I think you'll need a touch of genius.

Good luck though. I really want to see this done.

[Meathead316]

Re: Wanna try making a AA12 shotgun

USAS?!! Thats one ugly mutha!

Agreed that getting to to work first and then upgrading the power second is how it should be done, and was my intention :P (i was just stating the upgrades before someone piped up about a 330fps spring being split between 3 barrels not being strong enough..

3 barrels and 1 aeg gearbox is the plan, and in theory shouldnt be too hard to mske it happen. I look apart my tri-shot TM m203 (to see how it worked, and i didnt wanna risk not being able to reassemble my shottie that i love!) anyways, its quite a simple principle and if youve seen inside a tri-shot you know what im talking about, if not youll just have to wait and see (but basicall 1 nozzle will become 3, simples..... i hope!)

3 round burst instead of a true burst would be cheating! also how would a full auto 3 round burst work exactly? i know u can get burst chips or whatever, but a full auto burst seems to be a bit ludicrous/redundant...

i agrees that using the barrel and feed system (with a bit of modding) from a tri-shot shottie will be the best way to go. But i have to disagree with modding the piston in the aeg and swapping it for a triple cylinder system. Yes it could be done, but why not just have the nozle split into 3 instead?

Anyways today i carried out some tests (nothing too fancy just power comparison and the 1 cylinder sharing its air concept)

Basically what i did was buy some felt tip pens and made small barrels out of them, i then use a piece of cotton to stop a bb falling out of the end. This end was then secured (leak free) to the end of my spring powered single shot shotgun (300fps) and a bb was then dropped in and fired. now with the barrel being 4 inches long and a loose fit (7mm) with no hop to speak of, the bb still traveled almost 100ft.

I then made 3 more identicle pen barrels and taped them toether to form a triangle. I then fashioned a 3-1 adapter and attached it to my gun, loaded each barrel with a bb and fired, hey presto hey all flew out at the same velocity, albeit it less thatn the single barrel.

Also worth noting, while in the 3-barrel setup i loaded only 2 barrels with bbs leaving 1 barrel empty, i then pulled the trigger and the bbs went barely 15ft... so a misfeed will definatly not make the weapon hot.

tomorrow i will attach my tri barrel to my r700 (400fps) and my dragunoz (almost 500fps) to see how the added power reflects on bb distance.

I am fully aware that i will not be able to use this to snipe any body with, and that is not the purpose of a shotgun, the idea of this project is to make a weapon that makes cqb players poop them selves, and something to provide surpressing fire with.

Anyone wanna sell me an M4?

[jonny lovegrove]

Its not pretty but easier to make from an m4 :P
Tbh id rather someone made a Pancor Jackhammer, seeing how it was classified as an assault rifle :L


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[Grounded_Pilot]

Re: Wanna try making a AA12 shotgun

You could see if you can get a FA-MAS magazine to fit.

Then you've got the long straight mag thang going. Damnit!! Now I want to have a go at this!

The only issue I can think of is the whole making a "shotgun-like" barrel/firing mechanism... I can't remember how the piston set up looks in an old M56... and if it could be customised/placed in a geared AEG...

[Figjam]

Re: Wanna try making a AA12 shotgun

i agrees that using the barrel and feed system (with a bit of modding) from a tri-shot shottie will be the best way to go. But i have to disagree with modding the piston in the aeg and swapping it for a triple cylinder system. Yes it could be done, but why not just have the nozle split into 3 instead?

Like I said, I think the problem will be in the event of a misfeed, which with my tri shot does happen a fair bit. The way the tri-shot distributes the 3 BBs into their respective hop chambers is quite finicky, so probably at least once out of each 10 burst cartridge I'll get a shot with only 1 or 2 BBs not the full 3, and this almost always happens on the last shot as I rarely manage to squeeze the full 30 BBs in. With a triple piston system its no problem, because when the pistons compress an even amount of pressure is put down each barrel no matter if there is a BB or not, but from a single piston divided into an outflow of 3 nozzles I'd expect that if one chamber didn't have a BB in, the majority of the pressure would escape down that one and leave the other two barrels in danger of not even having the pressure to clear the BB, at which point all sorts of jamming issues may start happening.

I could make the much shorter point: if a single cylinder worked, why to TM go to the effort of doing a complex triple one?

But, as I said earlier, I want to see you succeed. If it does turn out that a single cylinder works that'd be awesome, because it makes doing this way easier than I imagined and I'd probably get off my butt and try it myself! But if it turns out you do experience these troubles, I hope my advice will be handy. I still definitely have wood for your project!

[Meathead316]

Re: Wanna try making a AA12 shotgun

Very good points!

I agree that 3 pistons would be better, but it then means modifying the gearbox. so if i can get away without doing it, then i will!

My TM M203 sometimes misfeeds, where as my big shottie has never done it...

The feed system is quite complex and has a little arm thingy, but im hoping that it is not essential. as it would be more faff an dmore to potentially go wrong.

Today I played with my little pen barrel thingies using my sniper rifles.

The almost 500fps dragunov sent the bbs with no hop and loose barrels about as far as a single bb from my spring shotgun with hop. so i recon a 450-500fps spring will be what i require when all is said and done.

Thats all for today, still after donar guns, and for cheap! Im hoping to spend about £40 on a trishot and £70 on an M4/M16. remember i need no mags or accessories with these and they can be cosmetically garbage!

[Meathead316]

Re: Wanna try making a AA12 shotgun

Right, had another look at the parts from a trishot required to make it work. This combined with the input from another memeber on the technicalities of the laoding arm has made me come to the decsion that the existing trishot system will not marry all that well with an aeg. I think it could be joined together ok, the nozzles would be easiest, the loading arm would be a right pain as even a blowback aeg doesnt recoil as much as the pump moves on a spring shottie, but even if that did work, the loading arm needs to push the bbs quite hard, and a little motor driven thingy isnt gonna have the same strength as manual pumping.

so the airsoft AA12idea is now dead in the water.....

But, as quickly as i relaised it would work thsi way, i had a light bulb moment.

An outer barrel with an inside diameter of 25mm will fit the 3 barrels side by side, this way i just have to duplicate the simple standard feed system of an aeg for each barrel (custom jobbie as it will have to be all slimmed down) and with them being side by side i will have access to the tops of each barrel making an adjustable hop possible. and to prevent jams and a complex feeding system, the mag will also be custom, and will be more liek 3 mags in one, a seperate mag for each barrel.

so i am no longer after a spring shottie, but i am still after a metal gearboxed M4/M16 (for cheap!!!) and 2 spare barrels.

This is easily the best and most simplest method i believe and i cant wait to get hold of an AEG to test it out!!! (some one make me an offer i cant refuse!)

[Figjam]

Re: Wanna try making a AA12 shotgun

Was thinking more about it today and thought much the same, basically a triple mag is easiest! Lots of winding though unless you go mids!

[Meathead316]

Re: Wanna try making a AA12 shotgun

mid caps ftw, and if i use 90 rounders, it wil actuallt be 90 shots as there will be 3 mags. Ive taken a midcap m4 mag apart before and most of it is just cosmetic, you could make a mag out of a pipe with a spring in it if you wanted to. I think the only parts out of he mags i buy i will use will be their springs, the bb pusher-upperer (technical term :P) and the feed port. I will be sure to have the space for the bbs and spring the same in my mag design but i think they will be easy to make, and i will make them out of foam pvc as it is soooo easy to work with (cuts with a knife...) and superglue sticks it good and strong, and its quite cheap.

I have a PM called "are you after an M4 or version 2 gearbox" not read if yet, or seen who its from, but fingers crossed it bears fruit!