SpudFiles

So I came up with this idea, you guys are most likely going to tell me its stupid, and I should not do it, but I have a feeling it will work, and will possibly bring a new revolution to this specific sport.

Before I launch into all the details and what not, I would like to know some basics before I get started.

First question, how tight of a seal do I need for either hair spray or propane?

Second, what sort of igniter should I start out with? I have a old clicker, but the wires broke off, and it produces a tiny spark, worth nothing.

Third, should I use metal or pvc?

Now for what I want to use it for. I would like to make a rifle that shoots airsoft bb's. Since my friends love it when I build stuff that produces a loud bang, I figured why not make a combustion rifle. I need to know if a basic combustion will melt an airsoft bb on firing, or if it will just make it roll out the end of the barrel. Thanks in advance for the help.

p.s, let me know if there is a way to do this kind of under cover so my mom does not kill me.

Well first off there is no problem creating a combustion rifle and its a feasible concept and not really stupid at all.

You probably want a tight seal just like any combustion cannon.

You only need a tiny spark to ignite the mixture. It doesnt take that much energy to ignite the mixture. A bbq igniter will suffice but you can use a stun gun if you want, both will work fine but a stun gun will probably be more reliable in producing a nice spark.

Depends on what look you want. You can use pvc and it will work. Anything you use at under 2 inches will most likely be pressure rated. Metal has a nice look to it, however it will be more expensive and hard to get an ignition setup.

It shouldnt melt the bb either, it should work fine if you take into account that you are making a combustion bb rifle. It will be a harder undertaking than a pneumatic bb rifle.

There will be alot of things you will have to take into account especially on this scale with a bb combustion rifle. If you follow the same principles as a combustion you should have nothing to worry about.

Good luck

P.S. About the undercover part, there really is no way to do that, just do your projects away from your mom, and try to get her to like what you do. That will be the easiest i believe.

Who says you can't make a combustion bb gun lol
I made a combustion bb pistol but it was ghetto.
I would use PVC cause it's cheaper and you don't need metal.

Well I got the basic idea down, I have my mauser rifle stock which I could use. Plus with an o-ring detent, or two, I could make it produce a seal and it would help with the power. I may use steel, and just have the spark jump onto the steel so I don't have to drill it or anything. I suppose I could be an idiot, and attach a schrader and make a small burst disk and make it a hybrid, but it would take too long to reload.

An O ring would definitely be beneficial, and sparking idea sounds great as well.

You also don't need to attach schrader valve but a burst disk will definitely make it sound louder as a normal combustion.

Yeah, I don't know about the burst disk. I think I will stick to the basics. I need it to work every time I pull the sparker.

Well thats fine as well, a burst disk isn't necessary but it can improve performance with better build up of pressure. But its more of a hassle to reload every time.

And you can't really make it a semi auto if thats what you mean by pulling the trigger every time. The best way to do that is with custom combustion cartridges.

Yeah, I was thinking about those, buts its almost too much of a hassle. Plus I have to do this without my mom knowing until its done.

Yea thats true, I would stick with just a regular combustion.

Something to consider though is making sure you purge the chamber well, because it will probably be of smaller caliber, unless you want like a 2 inch chamber that should be easier to clean of spent gasses.

Maybe a hand held mini fan from a dollar store? When you open the chamber to put in more fuel, then you turn the fan on and hold it over the opening to suck the fumes out, then put in more fuel, fire, and then repeat.

Ya that should be good enough, with will help alot. You could try and mount the fan in the chamber too to mix the mixture and help combustion peak pressure.

Eh, hand held would be easier, and if it has a sprayer then I could put something like lighter fluids in it and then spray that along with the fan on to get a fuel air ratio thats pretty good.

this is actually a good idea, don't know if your planning on a rifled barrel yet but i'm here to tell you its not a good idea, doesn't work with this kind of stuff (i'd be happy to go into detail) im guessing your going for a bolt action kind of set up?

if you want i can post more on my bolt action sniper, its pneumatic, but is built the same way, just the force comes from a different source, your probably going to have to make alot of custom parts and fitting mods to make it fit a bb barrel,

and may i suggest a 1/4 ball bearing or even a 3/8? it'll do alot more damage and make much better use of the combustion chamber as far as damage goes you can buy a box of slingshot ammo with 250 1/4in ball bearings for like 3$, i personally like the 3/8 but its the same deal lol

also for hiding it from your mom, work on it when she's not home, and im guessing you have some sort of work shop to do this in (if not, might as well give up now) and if shes like my mom, won't even step foot in the place

I think the idea is that there's a certain novalty in shooting an airsoft BB. This is evident in the joy DYI (and all of us) get when he shoots them through coins and 1/8" aluminum plate.

That said, I think that a hybrid BB gun might actually be easier than a combustion. If you get a 10x mix in a secondary chamber, like a CO2 bottle, all you have to do is let a little into the primary chamber with an normally open valve, and have that valve close when you pull the trigger, but before ignition takes place. That eliminates mixing issues, metering issues, and venting issues. The only complications are that it requires metal, and now absolutely requires either an o-ring denant, or a piston valve.

If you wanted consistently, you could regulate the 10x mix down to like 3x. That would get you many more shots before the power starts to drop.

Eh, I think just the novelty aspect of it will be more fun.


"Produce a bang and scare the s**t out of your friends". I think it would be a perfect long range weapon, kinda like an airsoft 50 caliber sniper. You wouldn't need rapid fire if your 500m away from the enemy when most airsoft guns only go 150-200 feet.