Genesis CNC AR-10a 80% Build

[KULT]

Posted this on my local gun board and wanted to share if anyone is interested.

So finished up my first Genesis lower today, its going to the range tomorrow. I thought I would share some photos for everyone interested in them. I did the CNC at Arms Specialty and Tool (Much thanks to Gabe for all the help). Much Thanks goes to Randall at AR15 barrels for checking all the various 308 pattern parts for builds over the years and conversion services of AR-10b uppers to run Pmags / SR-25 mags. Sorry about the crappy cell photos, don't have my lighting with me at home.


Here is a run down of parts for the build. We have tested it with a variety of uppers for fit. We know it will fit and work with these uppers.

Knights SR-25 uppers (might have a bit of play)
LMT MWS uppers (might have a bit of play)
LaRue OBR / PredOBR uppers (might have a bit of play)
Armalite AR10a
Armalite SR-25 uppers (Out there but not for sale anymore)
Armalite AR-10b uppers (with conversion)
Mega MATEN - Fits just fine and will function but is a bit wider and doesn't match as much cosmetically

Geneisis will be working on their own uppers that have DPMS barrel nut / thread and high rail just like the mega. So you can run Knights rails.

Upper guts - Known to work
Armalite BCG's (both forward assist and no forward assist)
KAC / LTM BGC's
DPMS BCG's
JP BCG's
LaRue BCG's


Lower build

Genesis Lower - Genesis CNC | High Quality 80% AR Lower Receivers
10 Round SR-25 mag
Armalite AR-10 Parts kit with Tactical two stage trigger
Armalite AR-10A Bolt catch
Armalite AR-10A Mag Release
BB
Armalite AR-10 Buffer tube
H3 buffer
Armalite Carbine Buffer spring
Magpul CRT

I tested for function with DPMS / Knights and Magpul mags

LMT MWS upper

SR-25

SR-25 Upper

Mega

Genesis ar-10 80% build - YouTube

 

[BillyGoatMachine]

How was your range test?

 

[KULT]

Range test was good, it was just for function testing as this lower is going to have a 14.5 inch barrel on it with a perm pinned flash hider. Put about 200 round down range and tested with a bunch of mags. Ran it with the MWS upper and a Mega with LaRue PredObr guts.

 

[redhooker]

Looks great, very nice work! I wonder if the fit would tighten up if you had it anodized? A friend and I are about to embark on the 80% journey and are doing some research now.

 

[Delta4-3]

Looks great, very nice work! I wonder if the fit would tighten up if you had it anodized? A friend and I are about to embark on the 80% journey and are doing some research now.

Yes it would tighten it up approximately 0.002", depending.

 

[rideHPD]

What do you think of using it for a precision build? Anyone have any experience using any 80% lowers for one?

 

[KULT]

The lower is just fine, and since you cut it yourself you can match it to your upper. I used an SR-25 style upper to test, because that is what I had handy. There was no side to side slop just a bit of play from using undersized pins with an upper that was drilled for larger pins. Not an issue with Armalite uppers since drilled for the correct pin size or the uppers that Genesis will be coming out with. This lower is one of the best 80's I have seen . It is made from 7075 T-651 and the mag well is EDM cut. Much better than any of the DPMS style ones I have bought or seen.

 

[perkantino]

question for you. I got an AR10A lower for a build. I haven't been able to find an AR10A upper to mate it with. Obviously AR10B uppers won't work, unless you are willing to cut off (dremel) some parts, which I am not too fond of. What are uppers that will git the AR10A upper right. I heard MEGA will, but there would be a problem with the oversized pivot pin? Has anybody actually fitted an AR10A lower with something else with no mods?
If yes what are those options???????????

 

[KULT]

The quickest way is to machine an AR-10b to work, it is about 10 mins of work for machinist. That is what Armalite does, they just added a step to their CNC process. Megas fit but don't look right. Genesis is going to be coming out with a SR-25 style upper what will work if you want to run a KAC rail option. LMT MWS and LaRue OBR's also work.

question for you. I got an AR10A lower for a build. I haven't been able to find an AR10A upper to mate it with. Obviously AR10B uppers won't work, unless you are willing to cut off (dremel) some parts, which I am not too fond of. What are uppers that will git the AR10A upper right. I heard MEGA will, but there would be a problem with the oversized pivot pin? Has anybody actually fitted an AR10A lower with something else with no mods?
If yes what are those options???????????

 

[perkantino]

The quickest way is to machine an AR-10b to work, it is about 10 mins of work for machinist. That is what Armalite does, they just added a step to their CNC process. Megas fit but don't look right. Genesis is going to be coming out with a SR-25 style upper what will work if you want to run a KAC rail option. LMT MWS and LaRue OBR's also work.

How clean does the final product look? Essentially the lips have to be removed. I am sure I could dremel them off, but every time i ll look at those scapes it ll break my heart. Does Anybody do this professionally?
WHen is Genesis launching the upper?

 

[KULT]

Yes you can have AR15 BARRELS.COM HOME do it for you, the only thing you would see was a tiny machine mark on the inside of the upper. Genesis is going to doing the uppers in the next month or two from what I understand.

How clean does the final product look? Essentially the lips have to be removed. I am sure I could dremel them off, but every time i ll look at those scapes it ll break my heart. Does Anybody do this professionally?
WHen is Genesis launching the upper?

 

[perkantino]

Yes you can have AR15 BARRELS.COM HOME do it for you, the only thing you would see was a tiny machine mark on the inside of the upper. Genesis is going to doing the uppers in the next month or two from what I understand.

That's brilliant!