So are polymer lowers as shitty as I've heard?
Lowers were not designed to be made of polymer.
>>30320668
The only polymer lowers worth owning are the CavArms/GWACS lowers since they properly support the recoil assembly and fire control.
>>30320679
Correct, but if you kill a man the only thing you need to do is start a fire to melt the evidence. That and chuck the barrel and firing pin.
>>30320668
Not as bad as they used to be.
They did have problems at first, but I've held ARs built off polymer lowers that have been used and abused like any other AR with tons of rounds through it.
>>30320679
>2.28 MB PNG
>Lowers were not designed to be made of polymer
That depends on the type of polymer
>>30320668
More importantly is there any reason to use one over saving a few bucks?
>>30320686
I don't dislike the idea of polymer lowers, I just think when you decide to change the construction materials of a given object, no matter what it is, it should be redesigned. Otherwise problems may occur.
>>30320713
The only way you save money is if you buy a polymer 80% vs an aluminum one because of the jig.
>>30320700
It depends more on what fibers are in the matrix(polymer). I bet every "polymer lower" is actually a composite.
I have a .22LR ar with a polymer lower, I don't think I would trust it with my 5.56 upper on it, I'd be afraid the buffer tube boss would fatigue snap off, it works great for 22lr though, sweet little gun.
>>30320713
if you are building a lightweight gun. a truely lightweight gun where every ounce is cut. then you understand it will be fragile compared to a normal ar
>>30320668
Anyone ever try making a lower out of straight plastic?
Their solid. I have 1200 rounds through mine and Ive only had to epoxy some stress fractures around the buffer tube
>>30320668
>So are polymer lowers as shitty as I've heard?
yes.
>>30320668
http://www.gwacsarmory.com/cav-15-mkii-ar15-polymer-stripped-lower-receiver-black-ar-15/
Or you could just get an aluminum forged lower for about $60 and not worry about the durability of some shitty part.
Only option is Tennessee arms because he posted here and they're not shit
>>30322042
My TN arms lower is still holding up well after 1080 rounds of 7n6>>30322042
>>30322100
I kinda want to get one, but I don't really care about having a polymer lower
>>30321980
This is probably the only one I'd get, especially after that Inrange video. Too bad it doesn't come with a slightly shorter stock or some kind of adjustable LOP.
The only worthwhile one is that CavArms one seen in this thread. Now comes the question of why the fuck you'd settle for some fixed-stock polymer abortion when you could just get an aluminum lower with all of the customization it offers like a person who doesn't suffer from autism.
>>30322426
get the TN arms
>>30320668
unless you're trying to build an ultralight AR for reasons, just pick up a blister pack of 49.99 Anderson milspec lowers. It's a literal no brainer.
80% polymer lowers are easier to finish, but if you intend to manufacture a bunch of #ghostguns just buy a mill or plan to burn down the pawnshop you transferred 10 lowers through before the ATF men take the 4473s for the Clinton national gun registry.
>>30321645
barrel length?
>>30324205
18"
>>30321980
If only the had a stockless lower with a pistol length buffer tube
I own a Polymer80 lower and several aluminum AR receivers
The Polymer80 works fine. I've fired 400+ rounds through the upper, no evidence of stress failure/fatigue anywhere.
The flex modulus is higher on polymer lowers than aluminum, but the overall material strength is obviously less. Basically, it's more durable against impact, but won't withstand as much force as al 7075 can.
>>30320668
This might be a dumb question, but a polymer lower isn't the same as a carbon fiber lower right?
>>30321645
PSA build?
