Polymer80 80% AR pistol build thread...

[Lebowski]

It's a work in progress. I'll update this when there are more pictures and information to share.



80% lower is made by Polymer80, and it's made of a nylon polymer mix. Was easy to mill out, as you can imagine, and the included jig worked great. I still need to clean the trigger assembly pocket with a dremel but will do that at a later time or date. The plan is to build a 300BLK AR pistol of sorts. Bought the lower in "Fkat Dark Earth" but it looks more olive/green in person so probably won't mess around with trying to match it to other FDE parts and just do a two tone pistol: Everything else black.

Will probably update tomorrow sometime... expecting something in the mail.

 

[1911ly]

Awesome, Looking forward to the updates!

 

[trophyhunter]

So, that's being done on a drill press with a jig to guide your work? ~Very cool, if for no other reason than you built it yourself.

 

[AA&E]

I have one of these sitting in a box on the shelf. Been delaying it for over a year now. I've seen some brands of these receivers receive poor reviews online due to cracking under the stress and strain of recoil. Usually right at the rear near the buffer tube threads. I had contemplated a lower recoil round, but I'm not sure: a) there is an issue with this brand, it seems stout in construction and b) if a lower recoiling round would make a difference if the breakage is due to the impact of the buffer sliding and stressing the threaded region of the receiver.

Opinions on these concerns would be appreciated if anyone has any insight.

 

[1911ly]

My poly lowers manufacturer warned against using it as a pistol. They warned the buffer tower wasn't strong enough. I have about 500 rounds threw my poly without issue, but it is a rifle. I looked at the company website for Leb's lower and they do make a pistol specific lower. If he has that lower is is probably ok.

There are a lot of crap poly lowers on the market. Most have disappeared. Research the crap out of the lower you buy! Look for review. Mine is a James Madison.

I am looking forward to Leb's review. I'd like to build a pistol. This rifle is nose heavy. The receiver weighs nearly nothing.

 

[Lebowski]

Phase5 pistol buffer tube, Stike Industries grip and I tossed in a spare 20rd pmag for appearances.

 

[Lebowski]

My poly lowers manufacturer warned against using it as a pistol. They warned the buffer tower wasn't strong enough. I have about 500 rounds threw my poly without issue, but it is a rifle. I looked at the company website for Leb's lower and they do make a pistol specific lower. If he has that lower is is probably ok.

Introducing the new Polymer80 G150 Phoenix 2 version That's the lower I have, they do say a use of it would be a lightweight AR pistol. I'm hoping it'll be fine. Time will tell.

I'm aware that the weak point on pretty much any polymer lower is the buffer tube area. I'll be certain to inspect it after/before each use for cracks or any signs of failure. I can always replace it with a proper lower at a later date if I want to or need to. This is more just for fun than anything else.

 

[Psode27]

I just built two the other day. I have to say I am pretty impressed with the strength. Though I havent shot with them yet, I think where they beefed them up was a good idea. ONLY complaints were that my buffer tube screwed in really hard, though I was using an Ace stock folding setup, and that could be on the large side of the tolerances. The mags I had laying around didnt drop free either. They didn't stick, or fit tightly, but they didn't "drop free". I could probably fix that though if I cared more about it.
My setup was a cheap Skil drill press and a milling vise bought at Harbor Freight.
I will probably be buying a few more in the future just to keep for a rainy day. Though there are other options available, I see no reason to "shop around". I'm happy with the polymer80 ones.

 

[Psode27]

I just thought I'd drop some pictures off I took of my builds. Not to hijack....




I cleaned up the trigger pockets a bit with a dremel, Doesn't really affect anything if its not squeaky clean though. I intend to do a 300blk build on one someday soon hopefully.

 

[1911ly]

Phase5 pistol buffer tube, Stike Industries grip and I tossed in a spare 20rd pmag for appearances.

Introducing the new Polymer80 G150 Phoenix 2 version That's the lower I have, they do say a use of it would be a lightweight AR pistol. I'm hoping it'll be fine. Time will tell.

I'm aware that the weak point on pretty much any polymer lower is the buffer tube area. I'll be certain to inspect it after/before each use for cracks or any signs of failure. I can always replace it with a proper lower at a later date if I want to or need to. This is more just for fun than anything else.

I just built two the other day. I have to say I am pretty impressed with the strength. Though I havent shot with them yet, I think where they beefed them up was a good idea. ONLY complaints were that my buffer tube screwed in really hard, though I was using an Ace stock folding setup, and that could be on the large side of the tolerances. The mags I had laying around didnt drop free either. They didn't stick, or fit tightly, but they didn't "drop free". I could probably fix that though if I cared more about it.
My setup was a cheap Skil drill press and a milling vise bought at Harbor Freight.
I will probably be buying a few more in the future just to keep for a rainy day. Though there are other options available, I see no reason to "shop around". I'm happy with the polymer80 ones.

I just thought I'd drop some pictures off I took of my builds. Not to hijack....




I cleaned up the trigger pockets a bit with a dremel, Doesn't really affect anything if its not squeaky clean though. I intend to do a 300blk build on one someday soon hopefully.

They both look great guys I am glad to see some more 80% builders in this forum!

 

[Lebowski]

Looks great Psode27! After looking at their site again and your pictures, I see that Polymer80 sent me a OD green lower in a box labeled Flat Dark Earth (I ordered FDE and wondered why the lower wasn't at all like any FDE I've seen...)

Not a huge deal.

I may order the trigger group and finish out the lower next week after payday.

 

[RobbyMaQ]

See if I did this, then I'd have to invest in a drill press that wasn't out of round like my current one is...
Then I'd convince myself that I;d need a really good one, in case i did another 80% aluminum one..
At which point, I would tell myself to buy a mini milling machine...
Then I'd decided to buy a real milling machine...

Y'all are a bad influence I tell ya

 

[1911ly]

See if I did this, then I'd have to invest in a drill press that wasn't out of round like my current one is...
Then I'd convince myself that I;d need a really good one, in case i did another 80% aluminum one..
At which point, I would tell myself to buy a mini milling machine...
Then I'd decided to buy a real milling machine...

Y'all are a bad influence I tell ya

And you just explained why I have the machine I have now!! But I love it. I've made so many parts for everything from the tractor to a gun. Including pivot pins for the recliner I sit in. It's handy. Go for it! I have the Tactical Machining Gen 2 AR jig. I need to buy a few paper weights. They are either out, or I'm out of $$ lol. I'll be doing a build post soon on a TM 80% aluminum machining build.

 

[Psode27]

Looks great Psode27! After looking at their site again and your pictures, I see that Polymer80 sent me a OD green lower in a box labeled Flat Dark Earth (I ordered FDE and wondered why the lower wasn't at all like any FDE I've seen...)
My FDE was a Blum just FYI, it could be my pigment might be off a touch or something too. The finish of the plastic is slightly rougher in some area too. I'm not sure what the "blem" part is because it looks good to me. You could call and talk to the company if you wanted. The owner pops up in forums and seems to be a great guy and stands by his product. He might make it right with you or make you a killer deal on another one.
FYI for those who haven't been to their site, they are also releasing an 80% Glock 17 pistol lower.... very tempting too. I'm currently out of gun money though

 

[Lebowski]

Just picked up a Rainer Arms forged upper... https://www.rainierarms.com/rainier-arms-forged-mil-spec-upper-receiver

It was on sale and I'll roll the dice on it. This isn't going to be a high end build anyway. I'll let y'all know how it fits when it arrives.

In the mean time, I'm going to sand out the mag well until I can get a empty mag to drop free. There is some slight play forward and back which is good. It's not tight there. Only tight on the side to side.

 

[JTScribe]

My poly lowers manufacturer warned against using it as a pistol. They warned the buffer tower wasn't strong enough. I have about 500 rounds threw my poly without issue, but it is a rifle. I looked at the company website for Leb's lower and they do make a pistol specific lower. If he has that lower is is probably ok.

There are a lot of crap poly lowers on the market. Most have disappeared. Research the crap out of the lower you buy! Look for review. Mine is a James Madison.

I am looking forward to Leb's review. I'd like to build a pistol. This rifle is nose heavy. The receiver weighs nearly nothing.

Been looking at James Madisons, how are you liking yours? They reinforced the buffer from the reviews I read; I am wondering how it would work for a 9mm pistol build.

 

[1911ly]

Been looking at James Madisons, how are you liking yours? They reinforced the buffer from the reviews I read; I am wondering how it would work for a 9mm pistol build.

I am really happy with mine. I have no complaints. Mine is Gen 1. They recommended not building as a pistol. I just took a quick at their web site and I see nothing about not being able to do a pistol build (that I spotted anyway). I'd call them just to confirm.

 

[Lebowski]

Rainier stripped upper shipped yesterday. Should be here on Tuesday. I'm curious how it fits the poly lower, and will put it on my Anderson lower as well just to compare. I've read hit or miss reviews on them but for $50~, seemed like a steal and worth the risk.

 

[1911ly]

Awesome. Let us know how it goes!

 

[Lebowski]

Just pieced it together as a mockup for now. Grip and upper obviously aren't attatched 'properly', but this is what it'll look like soon... except, y'know, with a barrel and handguard.

On my last AR build I just bought a complete upper which I feel like was cheating. This time I want to build the upper as well.

Next order of business is probably a lower parts kit. I still need to finish out the lower, this includes sanding out the magwell a bit more so empty mags will actually drop free under their own weight and sanding the inside of the lower on the rear end where the take down holes are because it is absurdly tight back there and I can't push the upper all the way back (as seen in the photo) to get the holes to line up. The upper fits fine on my anderson receiver so it's not the upper. Not a big deal. It's polymer... easy to work with.


Slowly but surely coming together.