Casting an AR15 lower?

[the_natterjack]

Another thread has got me thinking.

I've seen lowers machined from a HDPE cutting board.



I'm thinking, would it be possible to make a silicone mold and cast an AR15 receiver in some sort of resin?

What do you think?

Brian

[bohoki]

sure why not

[CSACANNONEER]

Do you mean like Cav Arms, Plumb Crazy, Carbon 15s, etc? If so, that's a neat idea. I wonder why no one has thought of it before???????


J/K
Yea, you can make a functioning lower out of glass, metal, resin, plastics, wood, fiberboard, plaster, concrete, etc.

[kcstott]

Yepper!! as there is no real load being placed on the lower over all. The biggest issue is the buffer tube mount. That area is under a good deal of stress. But sure it could be made hell with the right amount of money involved you could have an injection mold made to make as many lowers as you like. Could make then from glass reinforced nylon just like HK and Glock and every body else now. Cost per part after the mold cost should be about $5 per lower for a lot of say 200 pieces. Make a 4 up mold and call it $3 each.

[the_natterjack]

Another thread was discussing the the idea of a "vending machine" that would mill an 80% lower into a 100% lower at the push of a button. No waiting period, no DROS, etc. as you were making the receiver.

So I'm thinking, rent a mold, mix chemicals, pour, and homemade receiver.

Brian

Do you mean like Cav Arms, Plumb Crazy, Carbon 15s, etc? If so, that's a neat idea. I wonder why no one has thought of it before???????


J/K
Yea, can make a functioning lower out of glass, metal, resin, plastics, wood, fiberboard, plaster, concrete, etc.

[darthnugget]

Carbon Fiber! Yum

If someone made a mold and pumped these out at what point would they be a firearms manufacturer and be required to register as such? Or should the mold be of an 80% and let the rest be done by the enduser. That way no DROS... Hrm what a good business oportunity to make 80% carbon composite lowers. In addition to money savings on material it would be easier to mill out even with a cheap harbor freight home made mill.

My father in-law just got one of those 3D printers. I wonder what tensil strength resin would work with one of those for printing an AR15 lower and firing it often safely?

This is awesome! Merry Christmas to me!

http://boingboing.net/2011/09/20/3d-printed-ar-15-parts-challenge-firearm-regulation.html

Here is a re-enforced one. When he told me he got one I thought it was neat now it will be awesome.

http://www.thingiverse.com/thing:11770

Resin site with tensil strengths

http://www.gpiprototype.com/services/objet-polyjet.html

[eaglemike]

Info - Looks like the tensile of the strongest material listed is about 20 percent of the 6061T6 family.

[kcstott]

I sure as hell wouldn't make one out of carbon fiber unless it was made 100% with some steel inserts.
Nop I'm talking about Plastic injection molding Just like the frame of a HK or Glock. very strong, durable, and very inexpensive to make. The mold is the expensive part.
Calvary arms already makes one but is has a A2 stock permanently attached.

As far as being a manufacture. well if you made one in an 80% configuration should be the same thing. The mold could be made to make 50%, 75%, 80% or 100% it's all in what you want the finished part to look like.
I will say that in my mold making experience it would be better for the molder to make it as a 100% part. The FCG pocket will present a problem with mold sink. If it was cored out at least partially it would make the molding process easier.

I know a mold shop that could build it and offer a 1 million part guaranty.
Mold cost would be 100K or better and that would take one hell of a group buy to cover that.