Fully custom milled body ... how stupid is it?

[ThinRizzie]

To preface this, I have 0 experience in metalworking (excluding shop class in high school) and no clue what I'm doing. I just have a hard time enjoying things like normal people. I'm also a cheap ass, so consider this more of a thought experiment than anything else. I'm thinking about making a fully custom magfed marker out of some other garbage I scrape together from other people's trash cans like a gas-powered raccoon. The only problem is that I'm not satisfied with anything unless it's 100% jank-ified, ridiculous, and impractical.

How stupid is it to grab some aluminum pipe and shove a marker valve in there? Are there any gotchas that keep me from doing this? Are there considerations I need to keep in mind while designing something like this, e.g. gas expansion space requirements, strength of material (is sch 40 enough?), etc.? Is it even legal for me to be messing with this kind of thing?

The basic thought is some kind of back-bottle design, keeping any gas routing (like macroline or something. I don't know the lingo) internal. I thought a blow forward valve (automag specifically) would be best for this so that I can minimize piping and keep it as small as possible, but I saw something somewhere that said the length of pipes acts as a kind of expansion chamber and it might not get enough gas if the piping is too short. Is there truth to that?

What's the smallest practical HPA tank I can get? I've seen those 3.5oz ones and that's cool but they're thicker than I would like to achieve my optimal design. I'd like to keep it to about 1 1/2" diameter. I'm not opposed to using 12grams if that's not possible.

I pretty much planned on copying the internal dimensions of an already-existing marker but changing the outside. I considered a shroud around an existing marker body but Mythbusters told me that if it's worth doing, it's worth overdoing 😂

[Drcemento]

This is MCB dude - you've come to the right place! its very ambitious for a first go around. I'd say look at the sheridan section here and pick up some brass - an old PGP and build out a simple single shot or pump and begin to understand the concepts involved with lots and lots of how to's. I finally bit the bullet and am almost done with a freak capable single shot PGP and i learned soooo much. look at Jordan's amazing work. and scroll through the custom projects section. you have some incredible help here to overcome obstacles. aluminum makes things hard. brass is more approachable. having access to some tools will help allot. super jank-ified in aluminum will be tough without a welder I'd imagine. post pics and dig in.

[Jonnydread]

I think you need to have a conversation with markdem

[markdem]

This is right up my alley. Thanks for tagging me

[Daltech]

For reference and motivation. The sniper pump Autococker was first built in a similar fashion.


“In late 1986, Bud Orr created the original Sniper pump marker by carving the works of a standard Sheridan PGP into an aluminum block that would accept a longer barrel. The Sniper was operated in a manner similar to pump-action shotguns in that it had to be manually recocked after each shot to load the next round. In 1987, Orr founded Worr Game Products to sell the products he was developing, and by 1988 he was running the business full-time.”

Do it for the experience. Sounds like allot of fun. Afterwards you will basically be a junior airsmith.

[BrickHaus]

I personally don't think a mag is a good candidate for something like this. Unless you simply use a mag body and put that in an aluminum sleeve.

Maybe an ion firing can is a better bet? Or like mentioned, a sheridan cart valve. But thatll be a stacked tube shooter.

[minimag03]

I agree. Think of the (2K9?) Micromag run, aluminum bodies couldn't hold up to the wear and tear from the spring and bolt without th aid of an additional SS insert, if I remember correctly. Also trying to place the exact pivot point for an automag sear in a 100% homebrew gun is already giving me a headache.

[ThinRizzie]

Yeah stacked tube isn’t what I’m looking for, but it’s a good idea. I was mostly looking at the automag because it looks pretty tiny but now that I compare it to an ion can it seems about the same size.

[markdem]

Oh, dude, you had me when you said you like janky impractical stuff. I love that stuff.

Yes, you can shove a valve into a pipe and have a pretty janky paintball gun. But Its hard to find a pipe that fits well. This is where a lathe comes in handy

you can build a gun from fairly weak materials, especially when dealing with low pressures. I have one that uses a 2 litre soda bottle as its air reservoir Because its operating at like 100psi.

I dont think any of this is illegal. But then again, ive never asked.

I dont know shit about automags so i dunno about expansion chambers or anything of the likes. I like poppet valves because theyre easier to make. Nelson valves are a type of poppet valve that lend themselves well to back-bottles because of their layout

Also, dunno much about tanks but the 13/3000 is pretty popular and easily available. Other than that, drill and tap a lump of metal to accept a valve and make any size tank you want

Making a standard paintball gun is fairly simple. Making it mag-fed is gonna be trickier. I would look at the Spyder/Kingman Hammer 7 for inspiration. although it sounds like you want a semi auto, i would consider a pump action from a simplicity point of view

[ThinRizzie]

I ... you WHAT?! I had to stalk your profile a little to see this thing in action and it's insane. This is exactly the kind of redneck engineering nonsense I'm here for

A custom tank sounds like it would fit the spec best, but would a field even fill it? Would I need to get it hydro tested? And what thickness / grade of material would be required?

[markdem]

ThinRizzie nobody will fill your homemade tank. Dunno if you can even get it tested. Gotta fill it yourself. And its pretty sketchy. I used plain old 6061 aluminium.

I dont like the tank - it freaks me out, but its possible. Safer using 12grams and you can get more shots from the same volume

[ThinRizzie]

Yeah I'm thinking that's the best option here too. I'm not going for a tony stark cosplay lol

[ThinRizzie]

This got way more traction than I was anticipating lol I’m going to try to do some more research into valve types and throw some reference photos together.

I appreciate y’all

[JeeperCreeper]

You know what Sheridans are? Valves shoved into brass tubes and stacked and soldered together.

I get stuff from Online Metals. Shipping is a little much, so I buy in bulk orders. But I almost always get stuff within 2 days, as long as its in the closest warehouse.

I believe netsurferdude2 has made a brass magfed marker.

Also grab a Dremel. I prefer the name brand one, but you can get any that you like. Amazon ones suck tho, way less power. Also grab some digital calipers.

[netsurferdude2]

I did a STEN similarly with an automag inside. Just go out and start putting stuff together.

[ThinRizzie]

This is almost 100% exactly what I had in mind!!! Do you have any plans or information on how you cut the tube to fit the valve in and hooked it up to the trigger / “receiver” bits?

[netsurferdude2]

There is an auto mag inside the main body tube. I bought the demilled STEN parts from a site. Welded them back together then put some time in with a torch and hammer to round them around the receiver. The front barrel shroud was fabricated out of spare tubing welded and drilled. The aluminum magazine well is aluminum soldered to the main body. Its about 90% complete. The gun shoots round ball great but keeps chopping first strikes. If you don't have metal working experience, this might not be the first build you try.

[Jordan]

You can use 11/16" Cocker internals inside of Sheridan barrel tube - I've built a bunch of markers that way.

The latest is a semi auto using Cocker pneumatics.

https://www.mcarterbrown.com/forum/c...rdry-a-brewing

[Chemical-x.....ahain]

I did a STEN similarly with an automag inside. Just go out and start putting stuff together.

Perhaps the best at heart advice there is here and in the truest spirit of the discussion.

[Chemical-x.....ahain]

I have a project that began as something else however im just going with the flow and ive given myself a few reroutes along the way, not in a way of finding something easier, but giving new challenges along the way, we grow the fastest when we challenge ourselves but it can be difficult at first to know where your skill / comfort level resides at first. most all of us have bitten off more than we can chew at times and perhaps we have to order a new part, scrap a design, or create a new path. The project is only done when you say it is. one of the things I love about this forum is that we are primarily here to encourage and of course show off our minty new oddities. in short dont be afraid of failure, most projects just need one or two parts if something goes haywire.

[COB]

I like your spirit. This is the place to get great useful information and advice. If you have no previous experience in creating your own marker, you may want to build some experience by starting with a "Poo" type build. My advice is to look at the "Poo Builds" section and see what others have done with junk markers or assorted parts. Then start with modifying a cheap marker into something close to what you are thinking. This will give you a base of knowledge to build your homebrewed jankenjager. I do not recommend building your own tank. It can be dangerous and have some tragic results. Consider existing CO2 or HPA tanks, or 12- or 88-gram CO2 carts. Currently, you are planning to dive in the deep end of the pool not knowing if you can swim. I suggest you start with a doggy paddle and build some experience. So, grab your water wings and start swimming.

[acrewofone]

Just a suggestion if you are running off of a single 12g CO2, but want to get more shots. How about a 2 - 12g CO2 setup?

I use this CO2 setup on my Nelspot and get around 50 shots (just happens to be a 50 round hopper)

Airsource Dual 12 gram Changer (originally designed for Airguns)
JT CO2 to Paintball Adapter (adapt Airgun CO2 to Paintball)

[Drcemento]

Holy S*#T - just when you think you've seen it all in homebrew concoctions! nice work!

[ThinRizzie]

oh HELL yeah!! That thing is awesome!

I had this crazy idea to do a low-rent version of an AGD 6 pack so this is exactly the kind of thing I'm looking for lol