Scratch build of semi auto in rifle

No machining experience, but I've been interested in the same thing. After looking into it a bit out of curiosity, I think it's totally doable, you just need to take the appropriate precautions.

Are you thinking of a gas system or no?

Using rollers or levers would be what you'd want if you're not using a gas system; flappers or a tilting breechblock would be for if you are. That should cut your choice in half right there.

As for information, rollers would probably have the most information out there that you can rely on.

I thought to use a gas system maybe a direct action like the ar/15 as it is a part less to machine.
It would also be good if it was easy to make from tubes as it would be less expensive then machine from blocks, but i could cast aluminium parts and machine from if needed.

The tilting block is intresting but i have not much info abourt it.
Why do you think that a roller locking bolt should not be used with a gassytem?

>>34155229
>Why do you think that a roller locking bolt should not be used with a gassytem?
Rollers are mostly used in roller delayed systems, which is a type of delayed blowback.

I'm not really sure what the advantages of using a roller instead of a fixed piece of metal would be in a gas system like the picture, but it seems like it's just one more complication for a homemade gun.

As for direct impingement like with the AR15, it might be less parts, but you should look up what it involves. The bolt and bolt carrier form a piston, then the gas gets pushed behind the bolt in the chamber formed with it and the carrier to push the bolt out, where I think it uses cams to rotate the bolt around. If you're not using a rotating bolt, you might have to develop your own way of unlocking instead of basing it on something else.

A short piston gas system would probably be easier, it's just a rod and a spring that pushes against something, and piston systems have been used in a bunch of different ways, so you have more ideas to choose from.

>>34155295
An ar 15 bolt assembly is heat treated and plated do you know if the ak bolt assembly do need the same treatment?
Have any one any experience with an ar-18 or plans of it?
I could make an ar-15 lower and then design a different upper and bolt assembly

>>34155384
I'd suggest making an electric furnace and heat treat stuff that needs it.

>>34155295
I'm guessimg with the "ar15" style gas system he meant just DI which is a perfectly fine system, easy to make and all.

Direct inpengment operated roller locked action would be quite nice i'd say. The thing with roller delayed actions is that you've got to get all the angles and bolt carrier/bolt weighs right. And if you're using a DI system you might noy even save any weight by going with a roller delayed.

OP take a look at this design, there are quite the many elements here you might want to consider copying from.

https://www.forgottenweapons.com/rifles/trw-low-maintenance-rifle/

Getting plans like that would be sweet

Rodney Freake
[email protected]

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I will now build a test single shot rifle and see if a gas delayed blowback can handle the .223 round in open or closed bolt.
As I have made blowback guns before, so this should be easy to make.

It may be an extremely hokey looking design but the old Gwinn Bushmaster had a design that just about anyone could duplicate. It used AR-15 cast off components where needed to avoid complicated manufacturing and simple techniques for everything else. No rear buffer system so it could be a bullpup or have a folding stock in a normal arrangement.

>>34154811
Look up the bolt of the Leader T2 rifle.

I was thinking about doing a similar thing OP, but was considering doing a long recoil shotgun, rather than a rifle, mostly because the chamber pressure is much lower and less dangerous, and long recoil because again, I figure it would be safer since everything is moving fairly slowly.

Perhaps something to think about

>>34156239
You're gonna loose quite some gas pressure with that design.

>>34154811
Have you thought about using flat pieces of metal stacked up and bolted together? That would make for a sturdy receiver. I think you would be best going with a tilting bolt unlocked by a long recoil, the entire upper reciprocates back to pull/push the bolt down/up in and out of battery.

>>34155295
>what it involves
You mean a tube shooting gas into a cup?

>>34158471
if you mean you gonna need a tiny fraction of a gram more of powder for the same results? then maybe.

File: AR-15 bolt.png (730KB, 1024x713px) Image search: [Google]

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>>34154811
well OP it's going to be a journey but you can get it done with a lot of setups and patience.

they probably use a grinder to finish the things though.

>>34154811
Ever look at the VG 1-5 Volksturm rifle? It fired the 7.92 short cartridge,.
>>34156239
Posted the successor of it, that German pistol whose name escapes me now.

>>34160184
If you bother making a locked action you can bother making a gas piston or gas tube setup to unlock it. Actually, making a short recoil or especially long recoil would probably be a lot harder than just simple has operated.

>>34154811
Just me or is this an ar with a stupid trigger mechanism?

>>34160184
>You mean a tube shooting gas into a cup?
Maybe you should've read the whole thing, because I didn't say that was the hard part.

>>34161120
I for one encourage discussion of non-gas operation. If the barrel doesn't need to be modified, you can use a barrel off a bolt action rifle. Globally, bolt action rifles are more accessible, and it means you can reassemble it if need be, if you catch my drift.

>>34161452
But the thing is that with a bolt action rifle unless you're gonna make your own barrel extension trying to mount your usual bolt action rifle barrel extension on rails or something is going to be a pain in the ass. If we're talking USA just using AR-15 barrels for 5.56 builds would probably be the easiest option.

>>34161343
Yeah well it was quite obvious that while he did mention the AR-15 he still meant just simple DI.

>>34161120
It's just a catch to unlock, the entire assembly is a big piece of recoil mass. It's probably the simplest way to build a self-loading firearm if you're stuck using primitive tools, there's a reason why gas systems were not in vogue until later on.

>>34161343
No that's pretty much it. There is no "hard part." If you want a dirt simple DI bolt carrier then use roller locks or a tilting bolt, either option gives you simplistic reciprocation without having to worry about timing rotation like an AR or AK uses.

Roller locks can be activated using a simple triangular wedge and a tilting bolt can have a big, fat locking surface that just relies on the carrier sliding it up or down. If you don't give a fuck about accuracy your parts can be sourced from shit like steel rods for rollers and a big piece of ground-down structural steel for a tilting bolt.