Best bolt-together lowers you've seen?

[NorCalAthlete]

Came across this one on Reddit:

https://www.reddit.com/r/guns/comments/dcvwxr/martian_surplus_ar/

I know we gotta have some machine gurus here somewhere. Based on the definitions of even an 80% lower, none of these parts even match that and thus shouldn't qualify as a firearm per ATF or DOJ or anything (though, IANAL).

Regardless, I'd be interested in tinkering with some bolt-together designs - imagine if we could start flat-packing lowers like they're from Ikea lol.

I'm also not sure why these designs need so many screws at the rear vs a couple larger ones. Not a structural engineer or mechanical engineer though so someone else may have a better clue.

[NorCalAthlete]

There's also this one in carbon fiber:

https://nozirohsystems.com/

[jimbo74]

Not sure how you would engrave that prior to assembly.......

[therealnickb]

Gonna need a bigger pic before I can pass judgement.

[bsumoba]

I guess the real question is why, when a lower is going for around $100 bucks plus tax and DROS. Not exactly breaking the bank with that cost.

[17+1]

[Dave Hoback]

These have been around for years to DIY’ers. Here’s an OLD thread!

https://www.calguns.net/calgunforum/showthread.php?t=274358

Plan on seeing more of these “kits” available next year. The plans/blueprints for 3D printing machines have been around for years. I don’t believe the 3D receivers are very durable, and certainly not geared towards precision/accuracy.

I use one brand of Billet 80% lowers for all my builds now. Every AR I have ever built was capable of SUB-MOA accuracy. I prefer using only 7075 T6 receivers in my AR’s. Now, I have nothing against the polymer receivers. They do work. Simply my preference.

The AR was designed for combat effectiveness, reliability, ruggedness and ACCURACY. I don’t want to sacrifice any of those qualifications. I started building rifles right after the Clinton AWB expires. And it was AK47’s. But it was the WANT of accuracy that led me to building AR’s. And I never looked back!

[saudadeii]

Came across this one on Reddit:

https://www.reddit.com/r/guns/comments/dcvwxr/martian_surplus_ar/

I know we gotta have some machine gurus here somewhere. Based on the definitions of even an 80% lower, none of these parts even match that and thus shouldn't qualify as a firearm per ATF or DOJ or anything (though, IANAL).

Regardless, I'd be interested in tinkering with some bolt-together designs - imagine if we could start flat-packing lowers like they're from Ikea lol.

I'm also not sure why these designs need so many screws at the rear vs a couple larger ones. Not a structural engineer or mechanical engineer though so someone else may have a better clue.

Yeah, well CA law still requires applying for a serial number and engraving it on the "receiver" before finishing. Not sure how that would work here.

There is a lengthy discussion going on in the National 2A forum on what constitutes a "firearm" as defined by the ATF. You might check it out.

As for the screws, earlier polymer lowers had a habit of developing a nasty crack at the rear by the buffer tube. Using more, smaller screws helps distribute shear forces more evenly.

The 2a discussion is here:

http://www.calguns.net/calgunforum/showthread.php?t=1564423

[17+1]

https://www.calguns.net/calgunforum/showthread.php?t=274358

[k1dude]

Came across this one on Reddit:

https://www.reddit.com/r/guns/commen...an_surplus_ar/

Ban all pieces of metal!

[ar15barrels]

Came across this one on Reddit:

https://www.reddit.com/r/guns/comments/dcvwxr/martian_surplus_ar/

I know we gotta have some machine gurus here somewhere. Based on the definitions of even an 80% lower, none of these parts even match that and thus shouldn't qualify as a firearm per ATF or DOJ or anything (though, IANAL).

Regardless, I'd be interested in tinkering with some bolt-together designs - imagine if we could start flat-packing lowers like they're from Ikea lol.

I'm also not sure why these designs need so many screws at the rear vs a couple larger ones. Not a structural engineer or mechanical engineer though so someone else may have a better clue.

Don't forget these:

https://www.theflatspot.net/ar-lower-flat.html

kt ordinance kt-15b lower (no longer sold)

[stix213]

There's also this one in carbon fiber:

https://nozirohsystems.com/

That is really cool looking. Do want.

[crufflers]

The one from Reddit looks amazing. Is anyone here actually shooting one made from flats?

[enorbit3]

i dont understand the appeal when you can get $50 anderson lowers or $80 aero lowers. I mean its cool to build your own, but id rather get an 80% if i wanted it to be completely off the books. Otherwise I wouldnt trust a lower that is screwed together like that.

Does anyone know what kinda durability or round count something like that can endure?

[crufflers]

i dont understand the appeal when you can get $50 anderson lowers or $80 aero lowers. I mean its cool to build your own, but id rather get an 80% if i wanted it to be completely off the books. Otherwise I wouldnt trust a lower that is screwed together like that.

Does anyone know what kinda durability or round count something like that can endure?

I hear that. I'd like to pick up a few when they go for $40 locally. That first one just looks gorgeous to me. Never seen a bolt together receiver before so novelty value I guess.