just as crappy as polymer.Do yourself a favor and buy a gun made out of metal

 

The Carbon 15 is not made of carbon fiber. it's a polymer, plastic that has a reinforcement fiber in it. Trying to produce a polymer receiver the same dimensions as forged aluminum has never worked out well. Google carbon 15 AR's and then make an informed decision or buy a forged rifle from Windham if you like there stuff.

 

CHEAP...not inexpensive. Build it correctly with Aluminum OR magnesium 👍

 

Thanks for the replies. I do own an AR15 with an aluminum lower and upper. I know Glock received a lot of negtive feed back initial (and still by some) about being plastic.

 

Thanks for the replies. I do own an AR15 with an aluminum lower and upper. I know Glock recieved a lot of negtive feed back initial (and still by some) about being plastic.

Different issues between polymer pistols and polymer AR receivers. For what you would pay for an AR with polymer receivers, you can buy an AR with forged aluminum receivers and have a more durable AR. Over the years, many of the polymer ARs have been hit and miss. I have seen some that are still rocking it today. Others have not faired so well. As was pointed out, once broken, there is no way to repair them. Personally, I would never recommend a polymer AR to anyone. I understand the premise for them being that they are light weight, but there is a trade-off. They are not as durable and strong as the forged aluminum receivers.

 

I do a good bit of work with CF and polymers...I would pass. No benefit and if it breaks, not repairable.

 

Quality 6061-T6 and even 7075-T6 aluminum AR receivers, or complete guns for that matter, are so reasonable right now I wouldn't even consider anything else.

 

True carbon fiber, or fiber reinforced polymer is very strong- and for most real world situations, more durable than aluminum-- look at NASCAR, F1, bicycles, and jet planes. The transition will be consumer and market driven, not true functional issues. It is not currently accepted by the AR crowd- nor would a polymer 1911-- too much traditionalist skepticism to overcome. So far the ones that have reached the market have much to be desired, primarily because they are too cheap..... a properly designed polymer or fiber receiver should be double the price of the aluminum counterpart to set itself apart-- call it Porsche/Berretta/HK/Sig, and it will sell like hotcakes.

A well designed receiver does not have to be inferior-- but stress points need to be recognized and accounted for-- you cannot have a polymer reciver that looks and fits exactly like a standard AR receiver- that is the problem with the polymer receivers-- they try to be too close to the original, to appeal to the AR buyers, and be close or cheaper than the standard receiver. You have no problems using a polymer magazine, handguard, stock, sights,-- why not a polymer based receiver?

Currently there are many non-AR platforms that successfully use polymer receivers: Tavor, SCAR, Sig, Aug, others. It can be done,

Tennessee Arms is trying witha hybrid design- I have not personal experience with theirs but I think they are on the right track with the brass reinforced buffer thread.

 

AK guys are buying up polymer AK mags!! go figure.

I think a carbon fiber bike frame cost many times more than the aluminum-- why not the same in guns.

If MAGPUL made a proper polymer AR receiver, there would be demand.

 

Good discussion. Thanks for comments.

 

True carbon fiber, or fiber reinforced polymer is very strong- and for most real world situations, more durable than aluminum-- look at NASCAR, F1, bicycles, and jet planes. The transition will be consumer and market driven, not true functional issues. It is not currently accepted by the AR crowd- nor would a polymer 1911-- too much traditionalist skepticism to overcome.

I'm going to disagree that aluminum is less durable.

Firstly, I'd be surprised if a carbon fiber mag well would hold up to repeated reloads with aluminum mags. Carbon fiber simply doesn't have good abrasion resistance. Look at the front of a CF handguard on a 3 gunner's rifle. It's chewed up.

Also, I know nothing of aviation, but I do know a little about racing. There's a reason why most race cars use CF on quickly-replaceable parts, but not the chassis. You can get more rigidity for the weight, and for things like dive planes, a splitter/diffuser, a hood, a fender flare, a wing, wheels, etc., that is what matters. But those parts don't flex much. You shunt a tire wall with them, they're done, for the most part. The chassis, on the other hand, is aluminum, and even until recently, was steel.

Now, F1 cars, and even many LMP cars, to my understanding, do use carbon fiber monocoques in place of an actual chassis, with an aluminum mesh core or some other aluminum integration. And even then, yes, it's carbon fiber, but then we get to the real meat of the reason why comparing carbon fiber use in cars, planes, and just about everything else, doesn't translate to carbon fiber use on firearms.... And that is, the forces in a race track collision are transmitted to the monocoque differently than the forces of dropping your rifle on the buttstock... Those monocoques are surrounded by front and side impact protection (typically carbon fiber as well) that absorbs energy essentially disintegrate. There are also the wheels, engine, and general body work that also absorbs impact energy, as the monocoque is so low to be surrounded by all that. And further, any other car you hit has the same safety equipment, and most race tracks themselves have means of slowing a car down, and slowly dissipating the energy transfer from the wall to the car (tires, barriers, etc.).

So, the point of all that is to say that, where carbon fiber is currently utilized, it is largely in either a protected or disposable capacity. You don't have anything to give and protect the lower when the receiver extension gets run over, or dropped, or otherwise imparts force onto the receiver itself. And you don't have anything to buffer it from the actual abrasiveness of firearms usage.

I'm sure you could engineer an aluminum chassis with a CF surround that has protected edges, but I have to ask, what's the point? Aluminum is cheap enough, it's light enough, and it's strong enough... Tremendous weight savings can be made in the machine work of the lower, and just about everywhere else. I've seen the TN Arms lowers, they're smart designs. And I agree with you that there could be a case for alternative materials if the entire lower design is changed to suit that material, but like I said... I still question why.

 

The primary reason for CF is weight reduction for perfomance- no other real reason to do it...but then again it can be done, and can be done well, but not cheaply, nor cheaper You can make the argument that chromoly or steel can be used too, much cheaper and stronger than the aluminum-- then why the polymer mags?. Your impact arguments don't make sense, because aluminum and sheet metal fractures deforms, breaks and tears also.

Really, what is the intended porpose if the aluminum is good enough?....again the market demand (and consumer skepticism) is not enough to even manufacture a better than original polymer AR at this point--ultimately, most AR buyer are budget conscious. More efficient to buy a SCAR or a TAVOR in the intended design.

.

I'm going to disagree that aluminum is less durable.

Firstly, I'd be surprised if a carbon fiber mag well would hold up to repeated reloads with aluminum mags. Carbon fiber simply doesn't have good abrasion resistance. Look at the front of a CF handguard on a 3 gunner's rifle. It's chewed up.

Also, I know nothing of aviation, but I do know a little about racing. There's a reason why most race cars use CF on quickly-replaceable parts, but not the chassis. You can get more rigidity for the weight, and for things like dive planes, a splitter/diffuser, a hood, a fender flare, a wing, wheels, etc., that is what matters. But those parts don't flex much. You shunt a tire wall with them, they're done, for the most part. The chassis, on the other hand, is aluminum, and even until recently, was steel.

Now, F1 cars, and even many LMP cars, to my understanding, do use carbon fiber monocoques in place of an actual chassis, with an aluminum mesh core or some other aluminum integration. And even then, yes, it's carbon fiber, but then we get to the real meat of the reason why comparing carbon fiber use in cars, planes, and just about everything else, doesn't translate to carbon fiber use on firearms.... And that is, the forces in a race track collision are transmitted to the monocoque differently than the forces of dropping your rifle on the buttstock... Those monocoques are surrounded by front and side impact protection (typically carbon fiber as well) that absorbs energy essentially disintegrate. There are also the wheels, engine, and general body work that also absorbs impact energy, as the monocoque is so low to be surrounded by all that. And further, any other car you hit has the same safety equipment, and most race tracks themselves have means of slowing a car down, and slowly dissipating the energy transfer from the wall to the car (tires, barriers, etc.).

So, the point of all that is to say that, where carbon fiber is currently utilized, it is largely in either a protected or disposable capacity. You don't have anything to give and protect the lower when the receiver extension gets run over, or dropped, or otherwise imparts force onto the receiver itself. And you don't have anything to buffer it from the actual abrasiveness of firearms usage.

I'm sure you could engineer an aluminum chassis with a CF surround that has protected edges, but I have to ask, what's the point? Aluminum is cheap enough, it's light enough, and it's strong enough... Tremendous weight savings can be made in the machine work of the lower, and just about everywhere else. I've seen the TN Arms lowers, they're smart designs. And I agree with you that there could be a case for alternative materials if the entire lower design is changed to suit that material, but like I said... I still question why.

T

 

With the current poly lowers that I've seen coming into the shop I would stay away from anything like it. Get a normal aluminum lower, better quality and it will have less if any problems.

 

The Carbon 15 9mm has been a gtg gun for me. Easy on eveything & handles well.

 

"Carbon" is a marketing gimmick to make you think you are getting something decent (and high tech) when in fact you are getting cheap plastic (technically carbon based) with some sort of fill in it. At least BM is using aluminum upper receiver now after all the breakage experienced with the plastic uppers.

There is a difference between a firearm designed and tested to use a polymer receiver from the start and a firearm that was not designed for and did not go through R&D to have a polymer receiver. But that fact is lost on too many people. It is damn good registered M16 receivers are forged aluminum so they can repaired. For what they cost these days one kaboom or screw up when installing a trigger guard and etc could make you cry for a very long time.

I have a poly receiver I got for the hell of it, its junk. No way I would trust it to hold up if I'd get a stuck case and needed to nail the charging handle to remove it. Though some are better than others so if you want one do your homework. For range duty a poly lower will do in most cases, however considering how cheap a forged aluminum receiver is there is no point unless it is for a super lightweight build. Though I would rather use the aluminum/magnesium lightweight lower vs a poly.

 

I don't even know why carbon fiber is even mentioned in this thread because this gun isn't made out of it.

I bought a Bushmaster Carbon-15 for my adopted dad probably close to ten years ago. His shoulders were all jacked up and every ounce counts. He was able to shoulder and shoot the Carbon-15 but not the other ARs and he had fun with it.

Later on he lost interest and I sold it off at a pretty good price during the Obama gun ban scare.

My adopted dad didn't drag it through the jungles of 'Nam. Nor did he use it to defend against the Huns at Stalingrad. The gun worked fine for what it was intended for.

 

Personally I would not buy one, but my Dad did a few years ago.
He did it against my advice I should point out.

His is a Bushmaster Carbon 15. This is the one with the poly upper and lower with the optic. We shot 2K rounds though it a couple summers ago with zero issues. No breakages, and no stoppages.

A person can take that for whatever it's worth.

The upside was the weight of the thing. The downside was that the only magazines to drop free were Lancer 20 rounders. It's a decent gun and it was cheap, but if I needed cheap. I'd go with a PSA , or Anderson.

 

It's a decent gun and it was cheap, but if I needed cheap. I'd go with a PSA , or Anderson.

Even if I wasn't going cheap, I wouldn't rule out an Anderson lower. I had one on a rifle I assembled and later sold. I couldn't find anything - at all - wrong with the Anderson lower. I just had a bunch of spare parts laying around that could be assembled into a rifle and wanted the money to assemble something else. A complete rifle was easier to sell that a box of parts (except at a loss). If anybody knows of issues/problems or why an Anderson wouldn't be just dandy - I'd like to know what they are.

 

Just some food for thought:

1. Dimensionally replicating a part out of a material with completely different properties as the original material may work, but it may not. The argument that a Glock, or a F1 car, or a bike frame is made from fiber reinforced resin/polymer and they work great is not the same because they were originally designed for the material. This is typically not true of a an AR upper or lower.

2. I have seen failures of the Bushmaster Carbon-15 upper (where the barrel enters the upper). Therefore fiber/polymer uppers are a no-go - at least in my opinion.

3. Lowers are different than uppers in terms of stress during firing. Firing stress is almost a non-issue (again in my opinion). The real test is how they hold up to everyday handling. The Calvary Arms had known issues with the ultrasonic welding of the molded "halves". Even for a well made fiber/polymer lower, the buffer tube treaded area is a weak point if abused.

I had a NFA polymer/fiber lower - my goals were to assemble a cheap and lightweight rifle. And it was that. I think I put the whole rifle together for <$400 (at the time) - and it was right around 5# (with a pencil barrel aluminum upper). A friend assembled one just like mine. They both are still running fine after 1000's of rounds down range. If I were worried about significant mechanical abuse (falling on it on uneven ground for example) and my life depended upon the rifle - this wouldn't be my choice. For about everything else, I'd be Ok with it if the trigger wasn't so terrible (the NFA's have an all plastic FCG except for the springs).

If a lower breaks, it isn't the end of the world. You can buy/make (like James Madison) another plastic lower, or replace it with a buy/made aluminum lower. A failure of an upper during firing is a different story.

 

CF is a generic term, and it depends on the material used. To my knowledge, no one has really tried to do a good CF receiver for the AR or any other gun - the cost and utility would be prohibitive. Actually, there is no need to use CF, since cheaper, more workable existing "polymers" (nylon 6-6) curently used would be just fine if designed right.

Just because it is not being done, does not mean it can't-- but it has to be worth the while for a manufacturer to do it-- which in the vast majority of the cheap AR gun world, it would be a waste of time.

https://dragonplate.com/sections/technology.asp
http://machinedesign.com/materials/basics-aerospace-materials-aluminum-and-composites
https://www.qa1.net/driveshafts/car...ts/carbon-fiber-driveshaft-technology/benefits-of-a-qa1-carbon-fiber-driveshaft
http://sploid.gizmodo.com/heres-how-much-stronger-carbon-fiber-is-compared-to-st-1521751435
http://www.bactechnologies.com/high-performance-racing-products/carbon-fiber-1310-driveshafts
http://www.bactechnologies.com/custom-products/dot-high-pressure-cylinders

 

I thought I would ad to this thread.

Just ordered a 'Windham Weaponry WW-CF SRC.' (The CF lower & upper receivers.)

They have, from what I have seen, a proven track record with this model, over 3+ years.

It's 40% CF & 60% poly. You can't rightly compare them to 100% poly, which I have seen fail.

For $499 shipped, & a lifetime warranty, it was a no brainer for me.

Go ahead, fire away!

 

My Windham has been excellent.
I doubt you'll have any problems

 

While these aren't Carbon Fiber, these are two types of Polymer AR Lowers that are currently on the market. First off, the one I bought and DONT recommend:

This lower is Polymer with no reinforcement at all. While its the lightest, it definitely fits the bill of being weak and I would say downright untrustworthy. As you can see below, the buffer tube threads are polymer and I can squeeze the sides of the magwell in by hand.

Now, this is my Polymer AR that I trust just as much as my aluminum ones.

This one has a steel reinforcement made into the lower take down pin/buffer tube threads. As pictured here:

 

The upper also has steel barrel nut threads/pivot pin reinforcement seen here:

These two fit up together better than any of my aluminum rifles, nice and tight. The polymer is thick and is reinforced itself. I've got right at 600rds through this rifle. I hunt coyote with it and drag it out into the woods in WV where I live daily. I've dropped it multiple times but only from a distance of no more than 3 feet. So I can't attest to any further punishment than that. I trust it, just as much as my aluminum guns. I am a don't knock it til you try it kinda guy. I drank the polymer kool aid, I learned what to buy and what not. I love mine, so get one and try it out. Do your research, and judge for yourself. Good luck my friend.
Oh by the way, the steel reinforcement in my GOOD lower also encompasses the grip screw, steel threads, solid.

 

I have had a CF Bushmaster since 2005 and still have it.
I bought it because I wanted a CF AR pistol.
I would never buy another one.



But, on the other hand if it wasn't for the tremendous muzzle blast and noise I would have ten "plastic" KEL TEC PLR-16 pistols.


.

 

The upper and lower that I vouched for above is an ATI Omni. Heres a link to more info on the complete rifle: www.tactical-life.com/firearms/review-american-tactical-omni-hybrid/#american-tactical-omni-hybrid-ar-2015-hunter I built mine with the parts I wanted. But the complete rifle can be had for the same price as an aluminum entry level AR. Would I buy one complete vs. Aluminum? Probably not, but I built this rifle to be short, light and balanced. I vouch for the receivers, never tried a factory built one but if that's what your looking for then I would say your OK.

 

That ATI is still over 6 pounds. The 4 or so ounces a forged lower would add is worth the increase in durability IMO. Really a forged upper and lower receiver doesn't weigh much, a little over a pound stripped. The other crap you put on the rifle is what adds weight, though when you are concerned about ounces it all adds up. The price usually goes up a lot when you start counting ounces though. The V7 2055 enlightened stripped receiver set is only 12.2oz but you pay for it. Just like you pay for the super light BCGs like from 2AA and JP. But I'd rather pay the money for extra durability if need be.

 

I had a newer Bushmaster Carbon 15-- nice and light but didn't like steel ammo.. needless to say I sold it.

 

Those that make plastic gun are using a design for that model, Glock, Aug and a few I don't know. Again, trying to make a plastic receiver based off a design that called for a forging isn't the best idea.