Windham Weaponry Carbon Fiber AR-15

[warrlac]

This AR has a composite upper and lower. Does anyone here own one or have an opinion?

It seems that the pros are:

Lightweight
Inexpensive
Chrome Lined barrel
Inexpensive

Most reviews talk about the Windham Weapory spin from the Shot Show. It seems like the cons might be:

Upper to Lower fit
Parts interchangeability (I doubt a Carbon lower would fit a steel upper)
Limited accessory choices
Accuracy
?

Anyone have one?

Thanks!
Warren

[10-32 Solutions]

The lightweight advantages of the carbon fiber are offset by structural weaknesses of the carbon fiber. Lower receivers commonly break back at the rear takedown pin or around the receiver extension. Aluminum receivers are not that heavy that I would want to sacrifice their durability for a Bushmaster, and now Windham Weaponry, carbon fiber gun. They are inexpensive, cheap, and you will get what you pay for.

[george]

I have a few, none of which are Windham. A 16" 223 with carbon lower, all metal upper, a16" 300AAC with
carbon lower and all metal upper, a 300AAC 11" pistol with carbon lower and all metal upper. My others are all
metal.
Please feel free to nominate me for saint hood, that's three miracles, none have broken yet. I know of some earlier
carbons that have broken but maybe they are more durable now, I don't know. As I said, so far so good. May break
next time out, hope not.

[UnaStamus]

Companies that are doing the polymer lowers correctly are using specific metal inserts molded into the composite material. No clue whether WW has put any metal inserts into the receiver.
From a structural perspective, carbon fiber is incredibly strong in the direction of the grain. It is very weak across the grain. This is well known from the racing world. If you put loads onto CF from the direction it was built to take the loads, it is as strong as alloy metal at only a fraction of the weight. Put a small rock into the side of that push rod or pylon and it cracks and shatters with little effort. This is why it still has not been used in the aerospace industry for structural or exterior purposes.
I suspect that WW has used a cross grain layering system and they've used a lot of epoxy or binder to harden and reinforce it, but in the end CF is a very weak material from the sides. The result is that it has a 60% polymer construction with SOME carbon fiber material for reinforcement. You're not buying anything that hasn't already been produced by Bushmaster and other companies. In fact, this is likely the same design from Bushmaster.

As 10-32 Solutions said, the advantage of weight reduction is so minor that it's negligible. The weight difference between a forged 7075 T6 aluminum receiver and a typical polymer lower is 4oz. The average forged lower is about 8.7oz. When you compare 4.8oz to 8.7oz, you can tell that one is lighter. When you put together the rifle, you don't notice anymore because the weight is high enough for 4oz to not be noticeable. If you run a composite/polymer upper receiver, that's another 2-3oz dropped. Again, not much. There are ways to make a rifle lighter and still keep aluminum receivers.
I've also seen some broken polymer receivers first-hand. The stigma around them is well-deserved, believe me.

I know that some people own, or have owned, polymer/composite receiver ARs that work. However, I have yet to see one that's gone through the abuse or shot up to the round count that my rifles have and been issue-free. I'm not even that hard of my rifles either. If you don't have a lot planned for the rifle, you're probably not losing out on anything. If you plan to shoot a lot and maybe throw some abuse at your rifle, get forged or billet receivers.