[slog]

I'm definitely committed to getting a few of these New Frontier Armory composite lower receivers. I'm simply not buying the hype from some people that they're junk, because I have doubts they either own one, or they're comparing it to something of much higher quality. Meanwhile, there are those who are giving them rave reviews.

http://www.joeboboutfitters.com/New_Frontier_Armory_STRIPPED_AR15_Polymer_Lower_p/nfa-stripped.htm

These are not the same as PlumCrazy cheapo plastic receivers, and apparently are stronger than the Bushmaster Carbon receivers. Some people have complained about tightness of fit of some components. Others have noted the possibility of cracking. The cracking is what I'm worried about. Nobody has experienced this (with THIS brand) that I can find. One person even froze his, tied it to a string and slapped it against the concrete repeatedly with no ill effects. So I was wondering - technically - WHAT exactly would cause the cracking? Most of the brunt would be taken by the upper half where the bolt carrier is riding, right? And the springs would be absorbing much of the recoil energy, right? Please inform me.

[slog]

I saw this article wherein someone apparently ran over their NF polymer AR build with a tractor



http://www.702shooter.com/product-reviews/review-new-frontier-armory-lw15/

So I went ahead and bought a few.

[Triumphman]

The biggest thing with polymers is from heat. If you have a lot of heat buildup, the plastics will want to stretch and distort. Seeing that NFA is based in Nevada where there's LOTS and LOTS of heat, I'm sure they've tested this scenerio just to be sure that the plastic used won't give out. None of the article mentions if there's ANY metals fused in with the plastics? Nothing wrong with polymers in guns nowadays. I own a Hi-Point 40S&W, and it's held up quite well and Hi-Point came out long before Glock did with their plastic guns and look at how both of them are doing. Everybody is jumping on the polymer bandwagon now.
Del

[slog]

Originally Posted by Triumphman

The biggest thing with polymers is from heat. If you have a lot of heat buildup, the plastics will want to stretch and distort. Seeing that NFA is based in Nevada where there's LOTS and LOTS of heat, I'm sure they've tested this scenerio just to be sure that the plastic used won't give out. None of the article mentions if there's ANY metals fused in with the plastics? Nothing wrong with polymers in guns nowadays. I own a Hi-Point 40S&W, and it's held up quite well and Hi-Point came out long before Glock did with their plastic guns and look at how both of them are doing. Everybody is jumping on the polymer bandwagon now.
Del

Honestly, I'm still partly skeptical. I could have gotten the Delaware Machinery forged aluminum lower for $65 on RGUNS site, but this polymer would make great for a varminter rifle. I've seen quite a few people putting loads of rounds on them with the slide-fire stocks, and that's a lot of heat. I'm a more conservative shooter. By next year these things should be all ready if I can find some 1x12 twist bull barrels in my price range.

On a side note, I ordered them thismorning from joeboboutfitters.com, had the FFL faxed to them by 12 noon, and they shipped them out by 2:30. That's the fastest online transaction to shipping speed I've ever experienced.

[702Shooter]

Originally Posted by slog

So I was wondering - technically - WHAT exactly would cause the cracking?

This is a copy/paste from a response I posed about this yesterday:

Of the 10′s of thousands of these units that have been sold, around 40 have come back broken. Of those, only 4 were found to be defective. The others were broken from people trying to modify it themselves and/or abusing the weapon beyond any sort of reasonable actions. NFA still replaced every one of them.

The most common issue has been those painting the lowers, getting paint in the threads, then putting it back together and cracking the back of the lower with the buffer tube.

[slog]

Originally Posted by 702Shooter

This is a copy/paste from a response I posed about this yesterday:

Of the 10′s of thousands of these units that have been sold, around 40 have come back broken. Of those, only 4 were found to be defective. The others were broken from people trying to modify it themselves and/or abusing the weapon beyond any sort of reasonable actions. NFA still replaced every one of them.

The most common issue has been those painting the lowers, getting paint in the threads, then putting it back together and cracking the back of the lower with the buffer tube.

So I suppose putting loctite on the threads would be out of the question. I don't really care about the finish.

[702Shooter]

Originally Posted by slog

So I suppose putting loctite on the threads would be out of the question. I don't really care about the finish.

My understanding is that the issue is with dried paint build up. I wouldn't think that liquid or gel LocTite wouldn't be an issue but if it is, NFA will still replace it.

[slog]

Originally Posted by 702Shooter

My understanding is that the issue is with dried paint build up. I wouldn't think that Liquid or gel LocTite would be an issue but if it is, NFA will still replace it.

I'm sold. I should get mine within a week. Ordering more in the future for sure. These builds will be mostly for my little girls to go squirrel hunting and plinking. I doubt I'll have any problems with them.

[longunner]

This might have to be the lower for my first ever AR build...

[SSGN_Doc]

Well let us know how it works out for you. Most folks don't really run ARs very hard. I've recently read a couple bad reviews of the NFAs. One with recurring broken pins. Another with a break at the rear of the receiver.

I guess my main issues fall in a couple directions. I believe modern plastics are capable of being used successfully in firearms design. Many manufacturers have proven that. However, there is a significant gap in the design of the AR receivers and modern plastics. The AR was designed with dimensions that narrow an take advantage of the structural properties of aircraft aluminum. Those other successful firearms that use plastics were designed from the beginning to use polymer in the design and the polymer AR receivers do not make dimensional changes to strengthen weak points that survive when made out if aluminum. Plum Crazy, Hesse, Vulcan, bushmaster, and others all end up with failures in the same places. CavArms made a plastic receiver that worked well but it made structural changes to compensate for the change in material.
Aside from bushmaster where are the other polymer lower companies today. They make plastic receivers at a cost of about $20 a unit or far less. Sell them for a 400 or greater percent profit then close shop.

My next issue is that there are a lot of forged aluminum receivers that are about the cost of a pizza or two more. So why bother.