Casting AR-15 Lowers

they're out there for purchase but largely unused compared to aluminum forged receivers

>>30328525
I know but I was thinking about setting up a forge and casting some 80 lowers to sell. I know they aren't as durable as forged ones but hey that's why they'll be cheaper.

>>30328545
what's the point where making them isn't worth it though? you have anderson lowers at $50 on sale already. 80% aluminum lowers are $35-45 at cheapest

>Casts
I would even rather have stamped gun pats than cast.

>>30328693
Cheaper to make larger volumes of lowers for when I open my own gun shop eventually. Where did you find $35-45 80 lowers? The cheapest I could find are the weldable ones from theflatspot and the only others I could find under $50 are out of stock.

>>30328491
There's a super easy way to cast polymer lowers that was just posted. It's on ar15.com somewhere. You make a mold by putting a stripped lower in a box with silicone sealant.

>>30328737
I saw those kits you're talking about they look pretty neat however I still prefer aluminum over polymer if I'm going to cast a lower.

File: forging_zps17452d69.jpg (38KB, 612x416px) Image search: [Google]

38KB, 612x416px

>>30328704
Hey there Samuel Colt, what do you think nearly every AR15 lower and upper already is?

>>30328491
I toyed with the idea of 3d printing a lower and then using that to make mould and then casting it in aluminium. Then i remember I live in Australia and don't want to go to jail.

>>30328813
So any books on making these then?
>>30328982
Come to burgerland then

>>30328491
>Coating a receiver in a few layers of wax to create a mold

Do you understand how casting works?

>>30329049
It's used to make the receiver bigger since aluminum shrinks and that's for making the negative mold I'm not going to try and just pour molten aluminum over that.

>>30329020
1. acquire a commercial lower
2. build a box to fill halfway with a clay/sand mixture spray with release agent or paste wax
3. embed the lower in the box
4. bury the lower with more clay/sand mixture
5. bake the entire thing in an oven for a couple hours/days
6. carefully separate the two halves of the box to release the lower
7. trim away excess material
8. use wax to test the mold and make corrects as needed
9. after you have a good mold, try casting molten aluminum in it
10. machine the aluminum casting like any other lower
11. realize that it's not quite as good as commercially made ones, but will probably be okay if you follow machining instructions and check again blueprints.

>>30329105
I had this kind of general idea but I didn't know about the baking part what is the purpose of that?

>>30328491
>So with all these 80 lowers out there I'm curious has anyone read or heard anything about casting one?

No, because you don't have access to 7075 aluminum and a forge shaped properly

>>30329115
to harden the clay for the mold, tard

>>30329315
Not knowing a single piece of knowledge makes me a tard good to know.

>>30329115
yeah, I don't recommend what you're doing because you clearly don't even know what goes into machining a lower

>>30329326
That's why I'm trying to learn before I even attempt to make one.

>>30329322
see>>30329326

not knowing what you're doing makes you a tard

>>30329347
>That's why I'm trying to learn before I even attempt to make one.

Take my advice when I tell you that you don't have the CNC or the proper casts to make it cheaper than already existing materials

Might as well make billet because you'll have to buy aluminum stock to melt down anyway

>inb4 melting down scrap

>>30328737
AR15Mold.com Check it out. http://ar15mold.com/

I feel like it would require so much touching up that it wouldn't be worth the time. Metal casts tend to be pretty rough and aluminum can warp a lot from heat expansion. Real shops have CNC mills for the clean up. Fun as a project but too time-intensive for trying to make money.

>>30328813
The difference between casting and forging is in re-flowing the metallic grain in a uniform direction through heat treatment and mechanical work. A casting has no grain uniformity, which leads to weak spots in the structure. Especially in an AR-15 lower, where you have the lion's share of the stress focused on the thin rear portion where the buffer tube connects, it's crucial that you forge the receiver blank instead of just cast it, unless you enjoy having a 458 Carpenter steel implant in your shoulder.

File: 00002-2.jpg (165KB, 1024x768px) Image search: [Google]

165KB, 1024x768px

Newfag here, don't have an AR yet but personally I'd look into lost foam casting.
http://www.ar15.com/forums/t_1_6/1000194__ARCHIVED_THREAD____Legality_of_selling_wax_or_foam_machined_cores_of_AR_lowers_.html&page=2
You'll need to adjust for shrinkage but someday I want try a brass/bronze one for shits and giggles.
Alternatively there's this I just posted in another thread of you don't need aluminum
http://www.ar15.com/forums/t_3_4/676733_Fruity_Ghost___DIY_100s_of_ARs_cheaper__faster__gentler_.html
Have your 100%, silicone mold it, and cast your resin
https://m.youtube.com/watch?v=MSDovg_d5v4 [Open]

>>30329347
Other /k/ommandos have tried but have had problems with shrinkage. You seem to think you will make money off this. You won't for this >>30330969 reason and many other reasons. If you think you can open a 'gunshop' with this ass backwards thinking you need to either pull your head out of your ass or get prepared to fail and fail hard.

>>30331600
Don't bother with lost foam casting, lost wax plaster is cleaner and more what you want if you don't want to be spending forever grinding off voids. Also going to need a vibration source and a vacuum if you want to do it right.

>>30331723
So how would you get a wax model? Silicone mold a real one and cast wax into that? Also I'd dip in ceramic first, I think bronze is hot enough to damage plaster? Or yeah Al is low enough

>>30328491
You cant make Lowers out of your empty beercans faggit. So stop shitting up /k/ with these threads.

>B-but what if I buy 7075 ingots?
Even IF you could (and thats a big IF), get a cast without any airbubbles in it, its still not forged, and you cannot T6/artificially age 7075 aluminum cost effectively.

What you need to research is if someone ever had the idea of making a bolted-together, plate AR15 lower.

>>30331723

If you're using bronze you don't need all that.

Watch brothersbanzai videos on YouTube, he casts intricate bronze and brass things.

>>30331862
Yeah I thought assuming I used fine foam and sand (possibly petrobonded) you could down to almost fingerprint detail?

>>30331912

Lost wax investment casting is better.


http://youtu.be/8c2xiKFLnYY

You can even make a silicone mold for the wax.

Watch brothersbanzais vids, man.