/k/ - Weapons

>>588863

Luty is a great design, but it is a submachine gun. Rifles have longer ranges than SMGs, therefore rifles > SMGs.

The only real use I can see for a SMG in modern warfare is as a 'liberator' - where you use it to 'liberate' a better weapon from the enemy.

>>588859

Decent thread, but things like these already exist en-mass.

https://void.cat/bb2345de6a85558868d006906ae80ba918c03abf

https://void.cat/cac354e54e0467ecb9a5622312baae1767ece597

First one's really good

>>588871

Rifle cartridges involve higher pressures and temperatures, which complicate the design process. Joe McShlo, with not even the tools to make proper rifling, is not going to be able to make a homemade rifle that doesn't constantly run the risk of exploding in one way or another.

>>588877

So a easy to make rifle for the homebuilder is a pipe dream… could such a rifle still be designed for those with the skills and equipment to make them? Or would they be better off with an SMG?

>>588880

Noob question - wouldn't you need most of those things (lathe, welding equipment, sanding discs, and all the things needed for heat treatment and stuff) to make a quality SMG that wasn't going to blow up on you?

>>588891

No. You can build a STEN or Luty with common pipe and JB weld if it ever came to it. If the pipe can handle the pressure of standard ammo its good to go.

>>588892

Seems like I have much to learn. Back to lurking I go!

look up sine wave rifling benches. stupid easy to make, and the precision bits can be readily bought, such as the chuck, and the rack and pinion. then you just need bar stock, a drill press, and some bolts.

In very interested in a completely cold hammer forged receiver. Imagine a drilled block of steel goes in five minutes latter a completely functional receiver comes out and just needs a stock to be fitted a pre made firecontrol unit to be fitted and a barrel

>>588931

Why wouldn't you just use a rifling button and a hydraulic press?

>>588949

Off the shelf parts are hard to come by in certain countries.

>>589069

There are countries outside of America?

>>588877

On a more serious note, would press quenching or tempering strengthen steel enough for it to be used in a 5.56 rifle? Obviously reaching extremely hot temperatures would be very hard in a scenario where you would need to build a rifle from scratch. IIRC, oak burns at 900*F but I'm sure you could restrict the airflow or use charcoal.

/k/ has spoken! Luty SMGs are the way to go if you have to make a weapon.

>>588859

Is the ar platform not good enough? pretty much every part on those things has blueprints or alternative blueprinted parts made from any material you can feasibly get hold of effectively residing in public domain.

>>588859

OP this thread might be of interest to you

http://weaponeer.net/forum/forum_posts.asp?TID=10142&PN=1

Also, if Streloks aren't on Weaponeer and arent supporting then you are automatically wrong. Weaponeer is full of guys just like you and could use your minds.

>>589350

>joining weaponeer

Browsing will get you put on a list, actually joining will get you a personalized agent that will eat fast food under your bedroom window.

>>589358

Posting here isn't much better for you.

>>589366

8chan is milquetoast compared to weaponeer, Anon, who are you kidding?

>>588875

The problem with flapper locking systems like this one borrowed from the G41, is that they require a well matched set of flappers to work right or the system will try to put all of the force on a single flap and it will blow out. If you're going to do flappers at all they need to be set up to lock into the rear of the receiver like with the DP guns and be much larger for a margin of safety. That means extra material for a longer trunnion slotted into the receiver, more weight, more machining for people who may not have access to even a drill press, never mind a home shop CNC mill, and other problems.

I'm not saying that flappers are crap, they work, but they were superseded by rollers for a reason.

>>588931

Rifling isn't the hard part, drilling a barrel is.

>>589081

>oak burns at 900*F but I'm sure you could restrict the airflow or use charcoal.

Why would you use a wood fire to heat treat steel? You can make a heat treatment oven out of fire brick, nichrome wire, a thermocouple and a PID thermostat, all of which are fairly inexpensive, and there are guides online.

I'm looking into my own solution for how to make firearms at home, but it's slow going because I suck at understanding electronics, which are required for building the machine I'm planning to make.

>>589358

I wondered why there is a buxom cop under my bedroom window. XD

This rifle project definitely needs to happen, but as many other posters have pointed out, coming up with a rifle design that uses an action simple and cheap for the average Joe to build without specialized tools, is accurate and powerful enough to get the job done, and has enough reliability to not be too maintenance-intensive is going to be an uphill battle.

>>588877 (checked)

>Joe McShlo, with not even the tools to make proper rifling, is not going to be able to make a homemade rifle that doesn't constantly run the risk of exploding in one way or another.

I've heard of people using chemical etching to make rifling in the absence of the correct tools. This is fairly easy compared to dealing with the high temperatures and pressures of a rifle cartridge without access to heat treatment equipment. My thought was to solve this by designing it with a bull barrel, but you're making your gun heavier that way.

>>589659

>Swedish flag

It's probably because you missed your daily goat sacrifice to Womyn-Empress Merkel.

I wrote these posts in the other thread. I think they are pertinent to this thread as well.

>>588628

>>589533

>>589851

Electrical discharge machining is one option, but cast parts don't automatically have to be worse than forged or machined parts. This may be an option worth looking at for every part of the gun because forging or machining intricate parts is going to be difficult for a home builder. You can also use aluminum or polymer instead of steel.

>>589878

I just realized this can be construed to sound like I'm talking about casting polymers. I'm not actually sure whether or not this is possible. Polymers tend to burn, denature or undergo other methods of degradation instead of melting, but I suppose there could be some weird polymer out there that melts and can be cast into shape.

>>588859

Are there any commonly accessible ways to manufacture the cases of CT ammunition? Just polymer but what PSI need it withstand for, say, 5.56x45? Or does this require a bolstered barrel to take extra pressure the case cannot? I would figure so.

>>588859

Thinking rotating two or three lug piston driven for simplicity.

>>589886

That's probably a better choice than roller locking. You could also simplify the locking lugs by making them triangular, like on the Australian Leader Dynamics T2 rifle - https://www.youtube.com/watch?v=0hmJXqHoxac

And by making the design as similar as possible to better known designs (the AR18) it would make the R&D phase simpler. You would just have to take the AR18 bolt and recoil assembly and modify it slightly.

You could also use an AR15 fire control group to further simplify the design phase. Complete blueprints for an AR FFC should be included for those who can't buy them.

I've been thinking about the barrel issue - and I think the easiest way to do it would be to buy a barrel for a hunting rifle in the desired caliber, and modify it to suit our needs. You would need to remove the existing chamber/barrel extension and make one to work with the new locking lugs, but that would be a lot easier than making a barrel from scratch.

>>589878

>but cast parts don't automatically have to be worse than forged or machined parts.

There are several reasons why this is sadly not the case:

1. In order to cast something with the reliability of a forged part, it must be cast without voids. The only way to ensure there are no voids in the part is to cast it in a vacuum. This is impossible in a home environment.

2. Cast parts always shrink after they cool, and there is always some inconsistency in the process, meaning the cast part must be finished to size with grinding/filing/machining.

3. I mentioned this before, but there is limitation on what materials can be brought to high enough temperature with an electric furnace. In order to melt iron, an oil burning furnace is required. This will introduce oxygen and carbon to the steel being melted, which changes the chemical composition. Adding carbon to an alloy with a specific carbon content already in it will make the steel more brittle, and more likely to break under stress.

4. You will need something as the base for the part, either a plastic or wax investment part, or a larger example part to make the mold.

>>589881

Casting polymers is possible, there are two options: thermoset plastics at room temperature, or melting plastic at a relatively low temperature.

>>590685

I could have sworn I ran across some paper once about some dramatically improved casting methods that fix the void problem cheaply, but I can't find it.

>thermoset plastics at room temperature, or melting plastic at a relatively low temperature.

Even if you decide to go with polymers for the frame, you're not going to be able to use them for the most critical parts of the gun, so because this is supposed to be an easily built gun it's of questionable utility to bother with them at all unless you're a genius polymer chemist and you can create some wonder polymer strong enough to build every part of the gun from. A polymer like that probably won't be castable. Maybe there needs to be an open source wonder polymer project too so we can make the gun lighter.

For the action, the simplest route would be to do some form of blowback, though I'm sure you could make all kinds of wacky actions in a home gunsmithing shop.

Using design principles appropriated from Metal Storm's superposed charge technology and Dupont's Teflon bullet technology, you've got a gun that has few moving parts, is more cost effective, and produces much faster firing rates, muzzle velocities, and can be designed either for AP or total disintegration on impact of target without changing the calibre.

The only problems are that Metal Storm's patents are sealed, particularly on the propellant their designs use, and Teflon melts at such a high temperature that it is impractical for moulding, increasing waste- Dupont's researchers ended up milling their bullets which is more time consuming, wasteful of materials, and is generally a pain in the fucking ass.

But even still- figuring out either the exact propellant or using another viable propellant would turn this concept from impossible to merely somewhat taxing to build.

If any of you are interested, I'll explain in depth upon request.

>>591795

Superposed charges are a total meme. Even discarding the enormous difficulty of actually making one that works, you have a gun which:

>has shit-tier chamber pressure because straight walls and also your breech is a piston pressing down on a pile of explosives

>experiences massive variations in muzzle velocity due to the barrel becoming 2-3 inches longer with each shot (trying to compensate by using progressively smaller or slower propellant loads just worsens the first problem)

>can't be reloaded without replacing the entire barrel (MS tried various solutions to this, none of them are viable for rifles)

>can't be reliably zeroed due to the above factors

>is entirely reliant on a complex electronic igniter system of highly questionable reliability

>is prone to violently exploding from any kind of malfunction

You'd be much better off just making a simple falling-block or bolt-action rifle.