Is the Polymer Lower a Good Idea?

I've owned 5 poly lowers and have been around many more. The early plum lowers had issues with the receiver pins. That was fixed. The fit seems really nice and tight. However, I always swap out the poly receiver pins and poly trigger group for a mil-spec set. I prefer the feel of a trigger with metal edges and the pins have more flex than if like. The lower itself has proven plenty strong for my hunting. The only issue I've seen was on a buddy's rifle. Still not sure if the load was too hot, fired barely out of battery, or had a barrel obstruction, but the rifle blew up. Bull barrel split vertically from the chamber to 3/4 down, free float tube came apart, barrel nut cracked, upper receiver (aluminum) split, bolt split and carrier bent. The poly pin on the plum lower had the head sheared off from the expansion into the mag well. And the plum lower had a vertical crack on the front of the mag well, but the holes where the receiver pin held even though the pin had the head sheared off. Shooter was not hurt amazingly. Seeing how much damage happened in the metal parts of the upper and having all the gas from a split barrel funnel into the mag well and do so little relative damage to the poly lower made me a believer. I know there are weak points in the poly design, but they honestly take quite a beating before failing. I can't imagine treating my rifles in a way that would expose those weaknesses outside of combat. For the average hunter on a budget, they would be just fine. If you are in the habit of smashing and dropping your rifle regularly, buy the strongest one you can find. Lots of guys hunt with rifles with pretty wood stocks that are damaged much easier than polymer and never have an issue. It's all in how you treat your guns.
 
I just built a 6.8 using the NFA poly lower. The wieght is awesome and fits very tight with my upper which is a plus for hunting ( no slop noise), I did trade out the trigger group and a few of the lower parts. So far so good, I have alot of people ask me about these so I am trying to put it through a few paces so that I at least have an opinion based on experience. 250 rounds and no problems...also duracoat sticks really well to it.
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I can't wait to hear your report bushy. I have a NFA lower sitting in my safe. I was thinking of using it on my Dtech 20 tactical upper when it comes in.
 
Originally Posted By: BOBTAILSI can't wait to hear your report bushy. I have a NFA lower sitting in my safe. I was thinking of using it on my Dtech 20 tactical upper when it comes in.

I have a 6x45 upper down by Page AZ of you wanted to try it out...got a NFA lower there too. I won't mind...
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Originally Posted By: BOBTAILSHopefully they are stronger than the NFA ones cause my brother in law has broken 2 of those shooting his AR. That's reason enough for me to steer clear of all polymer lowers. He is shooting a Dtech 223 wssm for his cal.

Originally Posted By: BOBTAILSI can't wait to hear your report bushy. I have a NFA lower sitting in my safe. I was thinking of using it on my Dtech 20 tactical upper when it comes in.

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Some people would break an anvil given the chance. I'm not hard on my guns and it seems most people are having good luck with the NFA lowers. I'd like to see this question revisited in about 10 years when these lowers have had time to prove/disprove themselves.

I remember what people thought about glocks when they first came out, myself included.
 
Originally Posted By: doggin coyotes

Originally Posted By: BOBTAILSHopefully they are stronger than the NFA ones cause my brother in law has broken 2 of those shooting his AR. That's reason enough for me to steer clear of all polymer lowers. He is shooting a Dtech 223 wssm for his cal.

Originally Posted By: BOBTAILSI can't wait to hear your report bushy. I have a NFA lower sitting in my safe. I was thinking of using it on my Dtech 20 tactical upper when it comes in.

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I know, I know, but it was gifted to me so I figure I'm not out any if I try it...
 
Originally Posted By: doggin coyotesJust don't let your BIL use it and it'll be fine. Really.

I hear ya Larry, I think it may have something to do with his upper cause he said it was extremly hard to push together to pin it.
 
What seems to be forgotten here by some is the fact that the m16 when new had just as many problems as any other firearm if not more because of the materials that stoner was trying to use. If he had stopped because of the failures he had when begining this project there wouldn't be an m16/ar15/ar10 etc.

All that has been done now is take current lightweight materials and apply them in the same manner, nothing more and nothing less.

If a person does or doesn't want to use them it's completely up to them, thats America. And because it is you have the right to express your opinion whether you took the time to research what your talking about or not. blue
 
Originally Posted By: HereticAs always, Bushy, your camo patterns are the "stuff." Know what sticks to duracoat really well? Hydrographics!
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Originally Posted By: bluealteredWhat seems to be forgotten here by some is the fact that the m16 when new had just as many problems as any other firearm if not more because of the materials that stoner was trying to use. If he had stopped because of the failures he had when begining this project there wouldn't be an m16/ar15/ar10 etc.

All that has been done now is take current lightweight materials and apply them in the same manner, nothing more and nothing less.

If a person does or doesn't want to use them it's completely up to them, thats America. And because it is you have the right to express your opinion whether you took the time to research what your talking about or not. blue



It hasn't been forgotten at all. As I said in an earlier post, Stoner experimented with some very exotic materials such as titanium for barrels. Stoner also made sure he got it right before releasing the rifle. I don't care what the lower is made of as long as it works and is durable. But so far, poly lowers have come up short. Someday, someone will get it right. Probably whoever makes a metal insert for the receiver extension threads, FCG pins and where the pins hold the receivers together.

The early M16s had problems because MacNamara changed certain key specifications on production rifles without testing. The other early failure was the use of 6061 aluminum to forge the receivers from. Forging caused inclusions in the material that lead to catastrophic corrosion. When the switch was made to 7075, there were no more problems.

I'm not against lowers being made of polymers, just against lowers, or any other firearm part, that is less durable.

I will be getting a polymer lower for testing and hope to get it before Christmas. It's not in production yet, so that's all I can tell you. The folks bringing out this new poly lower have asked me to run it as hard as I would any other carbine and report my findings, good, bad and ugly. They tell me they are beefing up the design so it will be very durable. If anyone here would be interested, I'll post a report on the results in this forum
 
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Yes it's pretty safe to say that most or all of us would like to see that report when you get it done, please add plenty of pictures as well.

And thanks for making my point. blue
 
I picked up an NFA lower at the gun show last weekend. I am kind of curious to how it holds up. At times I can unintentionally be sort of abusive to the stuff I own. We'll see.
 
I have standard mil spec lowers and one plumbcrazy poly lower.

I use the poly lower on 6.8, 5.56 and a .22 lr uppers, besides replacing the takedown pins, there has been no failures.

I like both for different reasons.



 
I'm still using the the factory pins on the p.c. and did switch to steel pins on the NFA because of the red-x upper being so far out fo spec.

After a lot of work on my part the red-x is now working and took a nice dog on tuesday. If you have a tight pin problem it may be a out of spec upper, mine was.

You can find my problems by searching for "a tail of two companys" maybe it will help with any tight pin problems your having. blue
 
Built a similar gun bluealtered for a buddy. The NF lower fit tight on the red x. Peplaced the takdown pins. We used a 16" SS bull upper shoots amazing. But it doesnt cycle worth a crap with p mags. Tried a steel c products amd it runs like a top. I dot think the poly lowers are bad if you are on a budget. He has 550$ in the gun and it shoots well under moa.
 
Originally Posted By: filmitI remember what people thought about glocks when they first came out, myself included.


+1

But my thoughts on Blocks still stands, but not because of what they are made of! Your lower will not go through what a pistol frame will and look how long they hold up just fine.

I myself would rather have a standard lower but that just in case I every need to use my rifle as a baseball bat. But for a hunting our range toy you can't beat them.
 
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