Dang it - bought a polymer AR15 lower on accident

[Dr.Rob]

Perfect for a dedicated .22 build. CMMG makes some dandy uppers.

I got a complete poly lower from New Frontier Armory and it works just fine. If the trigger was better I might have left it paired to my Colt 6920 upper for an entire season of shooting.

 

[Nature Boy]

I wish my mistakes only cost $40

 

[shooter_from_show-me]

I've read the same. Something about the 9mm being a blowback rather than a modified DI, puts a lot of stress on the hammer pin and rounds out the pin hole in the receiver. I was planning a 9mm build on a poly lower myself, but am now going with my steel lower. Extreme overkill, but it'll be fun.

Yea I've heard these are pretty much required for a pistol cartridge AR pistol or rifle.

http://www.knsprecisioninc.com/nrthp/gen-2-non-rotating-trigger-hammer-pins.html

 

[justice06rr]

$40 isn't bad for a lower, but for a few bucks more you can get a standard aluminum lower.

These poly lowers are hit or miss. I have owned the same ATI Omni lower, and in my experience, it was not as reliable as aluminum lowers. The main issue comes on the buffer tube area with polymer threads--they did not hold up well with when tightening the buffer tube. The Gen2 model had steel inserts which corrected these issues.

But for $40, its not so bad. Use it to build a lightweight AR15 or maybe a 22lr. I would not recommend it for serious use (HD/SD or competition) but for casual range use it should be ok.

 

[ewlyon]

I bought a New Frontier polymer lower during the panic because it was all that was available and the price was pretty good for back then. It has gone through a couple different configurations but has functioned perfect from day one. The only possible criticism is that the takedown pin holes were extremely tight. The upper mounts very securely with no gap or movement. Even with an 18" heavy barrel and quad rail handguard it is not too front heavy and since I have a heavy magpul stock and a scope mounted I am glad to have the weight savings over aluminum.
I am also glad that there is no finish to worry about getting scratched.
That being said, at some point I will likely change it at some point to an aluminum lower, in the interest of long term durability.

 

[Warp]

I bought a New Frontier polymer lower during the panic because it was all that was available and the price was pretty good for back then. It has gone through a couple different configurations but has functioned perfect from day one. The only possible criticism is that the takedown pin holes were extremely tight. The upper mounts very securely with no gap or movement. Even with an 18" heavy barrel and quad rail handguard it is not too front heavy and since I have a heavy magpul stock and a scope mounted I am glad to have the weight savings over aluminum.
I am also glad that there is no finish to worry about getting scratched.
That being said, at some point I will likely change it at some point to an aluminum lower, in the interest of long term durability.

How many rounds?

 

[Dr.Rob]

I have run about about 500 rounds my M193 through on New Frontier lower and, Hundreds of rounds of 22LR. It's had no issues other than the ones I mentioned: a gritty feeling safety and a stiff trigger.

Full review here: http://www.thehighroad.org/showthread.php?t=642562&highlight=new+frontier

 

[ewlyon]

Warp, not many since I don't have much in the way of ammo money. maybe 1000 rounds total, 300 in its current setup since I built the new upper a few months ago. Probably a few thousand cycles of dry fire as well. As a side note the lower was stripped when I bought it, not the one with a polymer trigger pack.

 

[WestKentucky]

I know a couple of people who have the polymer lowers and haven't had issues, but they are basically range guns. However, you can find a ton of examples of those who don't have such luck. This picture illustrates one of the more common types of failures for the polymer lowers.



photo credit sumkrnboy on www.ar15.com

How? I don't understand. With a properly mounted rifle the shooter is firmly shouldering the gun. Eliminating flex at this point during recoil.

 

[Warp]

How? I don't understand. With a properly mounted rifle the shooter is firmly shouldering the gun. Eliminating flex at this point during recoil.

There is still stress there

Warp, not many since I don't have much in the way of ammo money. maybe 1000 rounds total, 300 in its current setup since I built the new upper a few months ago. Probably a few thousand cycles of dry fire as well. As a side note the lower was stripped when I bought it, not the one with a polymer trigger pack.

No offense to you, but it's not hard to tell when a person hasn't shot whatever firearm they are talking about all that much, and the "it's durable and lasts and doesn't break etc" claims kinda fall by the wayside when you verify that the gun doesn't get shot much

 

[yugorpk]

How? I don't understand. With a properly mounted rifle the shooter is firmly shouldering the gun. Eliminating flex at this point during recoil.

Its because the buttstock loosens up. It never really got tightened down that much to begin with and shooting loosens the threads up. Then when the owner goes to tighten the castle nut it snaps the back end off. I know. Ive done it.

 

[ewlyon]

I would consider 1000 rounds of 223 and multiple builds on the same lower to be a reasonable test of the lower in terms of construction. People have had bad experiences with polymer lowers from various manufacturers but I have no reason to believe that the NFA lowers are in any way less usable than a comparable aluminum lower

 

[briansmithwins]

I would consider 1000 rounds of 223 and multiple builds on the same lower to be a reasonable test of the lower in terms of construction. People have had bad experiences with polymer lowers from various manufacturers but I have no reason to believe that the NFA lowers are in any way less usable than a comparable aluminum lower

You may be on to something. I don't have any experience with $40 aluminum lowers, so I can't speak to their durability.

I would question the utility of buying multiple poly lowers vs one aluminum one that lasts longer than a case of ammo.

BSW

 

[Ibmikey]

Memorandum, I bought an ATI hybrid because it was cheap and I wanted a rifle that I could throw in the pick up and not worry to much about it. I did not want to use any of my 24 other AR's as a beater so the ATI got the job. The Hybrid has the metal inserts and so far has held up to 800 to a thousand rounds that were run pretty hard. The first shooting day I put it on paper and at fifty yards it put five rounds through one jagged hole, I need to try it again to see if that accuracy has been maintained after different shooters shot it smoking hot on several occasions. My ATI has a nitride finished DC Machine barrel that so far has exceeded my expectations. The major difference of course is the metal inserts that give the strength where needed and your lower lacks these important features so I guess you can go on a self destruct test or hide it in the back of your safe.