Silly Project in mind, care to comment?

Alright so, I've had a project in mind for a few years now, finally at a point in life where i can possibly begin work on it. I want to replicate a gun from the game/ book series Metro 2033, lovingly called the Bastard. In the game its a hand made "SMG" known for over heating and jamming, hence its name. Now SMG is a bit of a misname, since it fires 5.45x39 from an open bolt, but otherwise its abit like a really lousy sten. its got a top folding wire stock, and a short heavy barrel with a water jacket. where it gets weird though is its feeding mechanism. it doesnt use traditional detachable magazines, instead it uses a 20 round, double stacked box "clip" (ie no spring or feed lips) that it feeds through the gun from left to right. now the animation for it firing shows the clip housing (for lack of a better term) moving up and down as the gun fires, and this is the bit thats got me baffled. iv thought about just redesigning it to just feed from side mounted 74 magazines, which honestly makes more sense for post nuclear war moscow, but if it can be set up to work, id like to keep it as true to the original as possible. it will also need to be made closed bolt and semi-auto to be legal. this is just a project for fun, if you guys feel like flexing your creative muscles, id greatly appreciate input.

 

Cool, looks like something from Mad Max movies. Is it legal?

 

assuming it has over a 16" barrel...has an OAL of over 26"......is semi auto.....and fires from a closed bolt.....there is no reason it wouldnt be legal.

 

I'm not sure a 5.45x39 would work as a blowback (even closed bolt). You'd need to find some way to delay the bolt or just go with some normal gas system. If you have the faux water jacket on it, you might be able to hide an AR style low profile gas block and set it up as a DI gas system.

 

First off, listen to MachIVshooter he has some serious experience. That said, I have always wanted to build an operational 9mm Storm Trooper rifle. The basis for the original in Star Wars was a Sterling sub gun. Obviously, I would make it semi auto. The original for the films had a WWII tank sight. I would probably do something a little different. I have been tossing this around for a while, but always talk myself out of it.

If you have the itch to build, how about a Sten? Semi auto versions are pretty straight forward. I built a Mark V and it is a head-turner at the range and a blast to shoot. I learned quite a bit building the little carbine.

 

Sten gun. Please excuse the chipping paint. Part of that learning process I mentioned. I am going to wire wheel it and blue it. I thought all Sten sub guns were painted. I was wrong. I am planning a second Sten in a pistol configuration.

 

The feed system in the OP's cartoon gun appears to be an outgrowth of the Hotchkiss strip feed, modified into a double column box. The Hotchkiss bolt pushes the rounds forward out of the strip into the chamber. The reason the game gun feed housing is depicted as oscillating up and down is no doubt to align the two rows with the chamber in succession. See a real one in action at
http://www.bing.com/videos/search?q...&mid=7D0F0813FB1D1F191E5A7D0F0813FB1D1F191E5A

 

I'd probably crib off of a Type 11 LMG* for the feed mechanism. For blowback in 5.45x39 you're either going to need a ~8lb bolt or a delay. You could maybe get a gas blow forward delay in that size package, like the Volkssturmgewehr** assault rifle.

BSW

*https://en.wikipedia.org/wiki/Type_11_light_machine_gun
**https://en.wikipedia.org/wiki/Volkssturmgewehr

 

Ditch the water jacket.

 

You know what, building a Sten sounds pretty cool. I looked it up, and a parts kit is only about $100. I know there's more things than that needed to finish the build, but if it all comes out to the right price, I might be convinced to get a bit stupid.

What else would you need for the gun (barrel, etc), and what are the general steps for building it?

 

OK then. I got taking a look at this website:

http://www.indianapolisordnance.com/sten_mk3.html

By "receiver", do you mean that you just need the tube, like the ones they are selling for ~$100, or the kits that they want around $250 for? And to be honest, I've done very little machining. Can you realistically finish that receiver tube with a Dremel?

 

It'd be a pain to do, but roller delay like a G3 would easily handle 5.45. Alternatively use an inverse gas system like the P7 series of pistols. It would taking some work to make it work with the MUCH higher port pressure using 5.45.

-Jenrick

 

"By "receiver", do you mean that you just need the tube, like the ones they are selling for ~$100, or the kits that they want around $250 for? And to be honest, I've done very little machining. Can you realistically finish that receiver tube with a Dremel?"

There's more to it, I'm afraid. Practically all tube-gun parts kits are still in open-bolt configuration, which means;
-Modifications to the bolt to use a moving firing pin
-Modification to the FCG to use a hammer, or add a striker in line with the bolt
-Modification to the FCG to be semiauto (probably shoulda said this one first)
-Modification to bolt & tube & FCG areas so that unmodified full auto versions can't be installed (they call these 'denial features')
-Creation of 922r parts, provided your design is very similar to existing ones (original designs are 'native American' and not subject to import controls even if made entirely from foreign parts, but be sure you can defend that position in court if needed)

A receiver tube can be finished with a Dremel, as can all these other mods. But it's a question of time and skill when you don't have the best tools, in which case it's a question of money.

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Back to the topic at hand; super cool SMG-thingummy. It needs to live in real life.

+1 on the Hotchkiss strips. Totally impractical, but totally cool. Best of all, is a design using them is easily adaptable to belt feed from push-through links. It just so happens 9mm links are coming on the market, so bear that in mind. An RPD top-cover could potentially be salvaged for the feed-parts you need to advance the strip or belt. I would not bother emulating the Hotchkiss feed system

The cartridge may be somewhat incompatible with your design envelope (shape). A 223-class round really needs some sort of breech locking system. Theoretically a heavy bolt can do it, but it's both not been pulled off yet and wildly impractical even for a blaster. Your best hope at maintaining a tubular profile that is still locking-breach is either a modified HK roller delay (cocking tube/buffer trimmed off) or a VZ52 rifle. I'd encourage the use of the latter, if a barreled action can be had.

A pistol-power round would make things way easier, and a STEN trunnion could readily form the basis for the action. Cool project!

TCB

 

Thanks for walking me through the process. The semi-auto modifications are probably a dealbreaker. I kind of assumed that the parts kits came with some sort of modified bolt, as I didn't think they would just sell you a full-auto open bolt.

I'm certainly no MachIV when it comes to machining, and I doubt I could do much more than just cutting out pre-marked slots on a tube. $500 would be a tough way to find that out.

 

Umm...here's another idea...rather than make a full auto gun, you can easily make a pump gun which could be really neat. With the side to side magazine doomaflotchie you would need to use that very similar to a revolvers cylinder...except where a revolver ratchets in a circular pattern your bastard gun could ratchet side to side. Going this route you would need some pretty refined machining skills to set every chamber exactly right so that they would all be in time. As for 5.45 you could do that and heads pace it off of the shoulder. In fact, if I were tackling this project I would look for a beater revolver and just modify it. Skip the up/down reciprocating motion and just go for a side to side feed from a sequential chambered block. I would probably put a .45 barrel on it though just to make sure I wasn't out of time with a high pressure rifle cartridge detonating in my face.

I would build this...but make it look more like your "bastard"http://www.google.com/search?q=early+repeating+handgun&prmd=sivn&source=lnms&tbm=isch&sa=X&ved=0CAgQ_AUoAmoVChMI8_e6mKaCyAIVSf0eCh0YQQfs#imgrc=5RDWQY7aI02fxM%3A

 

i would be planing on making it a legal carbine, i had though about roller delays or some other form of mechanical delay. i also though maybe a maxim style feeding would work, where a claw grabs the cartridge from above the chamber and lowers it down to feed it in. the main hurdle is the racheting up down system. with no spring pressure to hold the cartridges in once the first is fed, i cant wrap my brain around how you would keep the rounds from bouncing all about as the bolt moves. a friend of mine has built some concept prototypes that functioned, sort of, the first fell apart, the second jammed a round at an angle and blew up, the third he did away with the double stack and did single stripper clips and it worked like a charm, sort of. unfortunately he did these before i met him and destroyed them soon after he built them (he lives in australia, nough said)

 

also i did look at the hotchkiss but the issue with how the game portays the gun is its litterally aa metal frame of a box. there is no spring clips or anything, the rounds are only loosely held in when all 30 or so are inside. i suppose if a proper ratcheting system could be thought up, and the clip was made like a double stack hotchkiss, it could work. the main point here is it doesnt need to function reliably, just safely. part of the fun, to me at least, is experiancing the gun as i did in the games... which is frustrating at best when you've got to fire more than a whole clipe through it quickly.

 

See, that's the difference between video game guns and real guns.

Video game guns don't really have to really work.

Real guns really do have to work, and Feed, Fire, & Function Freely.

That one won't.

Rc

 

I like the idea of using AK-74 mags and feeding it in from the side. Using a square tube receiver rather than a round STEN style one would make mounting a mag well easier.

A faux water jacket hiding a long stroke piston or DI gas tube would keep the appearance close enough to the game.

You could pretty much use an AK FCG and modified AK bolt.

Heck, you could practically use an entire AK parts kit and design your own receiver, grip, stock and shroud.

 

something iv considered is that the very essence of the gun is its imprompt. no two are going to be alike. this gives me some creative liberty in trimming down some more complicated bits. i think it makes more sense to make it feed from 74 mags, or at the least a hand made box mag, rather than trying to make a box feed left to right AND up and down. heck i could even use the faux water jacket to hide a piston collor and make it function like a gas trap style mechanism.

 

Eureka! i figured out aa way to not only take advantage of the faux water jacket but also make a simple system that would feasibly work very well and be lore friendly: gas delayed blowback. a port just infront of the chamber vents gas into the jacket, applying pressure to a large ring shaped piston around tha barrel, which is attached via op rod to the bolt. the high pressure counteracts itself, with the help of the recoil spring it holds the bolt closed until the pressure drops, then the recoiling force overcomes the remaining gas pressure, and the gun cycles. as far as feeding, either sten style with ak 74 mags for simplicity, or i have a couple ideas, but im ditching the up down motion, to complex.

 

Gas delay can be made to work, but not easy. I suspect you're either going to need to flute the chamber like HK did for the G3 or wax/grease the cartridges to keep them from being pulled apart as the bolt opens up.

The closer the port is to the chamber the smaller you want the piston to be to get the same force. 50,000psi at the chamber vs 10,000 or so at the muzzle.

BSW

 

The double stack strip could work if you use used something similar to a revolver cannon as far as chambering goes.

-Jenrick