Polymer Vs Aluminum Lowers

[Rouser]

I've been reading the discussions on the 80% polymer lowers in another thread. But having only recently become interested in building my own rifle, I'm not familiar with the pros and cons of the polymer units. Can anyone advise what the benefits of a polymer lower would be to an aluminum lower and vice versa?

 

[yellowsled]

NFA polymer lowers seem to have a good rep. Some vids also posted online during torture tests. I bought a couple as the prices seem to be very good. Only one failure I have seen online, and I think it was from overtighting the castle nut for the buttstock tube. NFA replaced the lower, no questions asked.

 

[Multifaceted]

NFA polymer lowers seem to have a good rep. Some vids also posted online during torture tests. I bought a couple as the prices seem to be very good. Only one failure I have seen online, and I think it was from overtighting the castle nut for the buttstock tube. NFA replaced the lower, no questions asked.

Didn't you build a carbine atop a polymer lower for your wife (or I think it was polymer) — how's it running thus far?

 

[KRONIK27]

Here's a thread on Polymer Lowers.
http://www.mdshooters.com/showthread.php?t=114657&highlight=polymer+lowers&page=2

 

[KRONIK27]

Have no issues with several of the Polymer Builds I have done. Function Flawlessly

 

[yellowsled]

yes, built the pink one. havent had time to shoot it yet

 

[Just5Guy]

I swear this debate is turning in to a Mac vs. PC, or Coke vs. Pepsi argument. I don't have any polymer lowers yet, but I will soon.

 

[Boss94]

I can't help it , I'm just not a fan of polymer lowers. I have seen a few cracked thru the rear take down pin. You can't go wrong with Aluminum its a well proven part that way!

 

[LimaVictor]

I have one in "probation" right now. I look at it as I am not taking a tactical training course where I shoot 2000 rounds in a weekend. Heck, more like 200 rounds once a month if that for me. Plus the price was pretty good at the time of purchase.
YMMV I guess.

 

[kohburn]

I can't help it , I'm just not a fan of polymer lowers. I have seen a few cracked thru the rear take down pin. You can't go wrong with Aluminum its a well proven part that way!

I don't think you'll see that with these new 80%polymer lowers - he really beefed up the area around the hole as well as the back strap connecting the buffer tube mount to the body.

I only recently switched my primary ar over to a spikes lower - used it for years with a plumb crazy lower with no problems. the plumb crazy is slated to become a 9mm

 

[ziptiespec]

I've been reading the discussions on the 80% polymer lowers in another thread. But having only recently become interested in building my own rifle, I'm not familiar with the pros and cons of the polymer units. Can anyone advise what the benefits of a polymer lower would be to an aluminum lower and vice versa?

I think the only cons right now are that the technology is still maturing. There have been issues w/ the poly lowers not being able to deal with the stress and cracks develop, things break, etc. That said, the lowers offered by Poly80 have been designed with these issues in mind and look like they'll perform flawlessly.

Pros for poly is obviously weight. Another huge pro is that an 80% poly lower will not require serious tools to complete. I can't wait to get my Poly80 lower!

 

[ObsceneJesster]

I don't think you'll see that with these new 80%polymer lowers - he really beefed up the area around the hole as well as the back strap connecting the buffer tube mount to the body.

I only recently switched my primary ar over to a spikes lower - used it for years with a plumb crazy lower with no problems. the plumb crazy is slated to become a 9mm

Maybe the new 80% Polymer lowers will have problems, maybe they won't. Either way, nobody will know for years. The same aluminum design has been around for 6 decades. This new polymer design isn't even in use yet. I see the lure in being able to finish them off with a hand drill but saying they are just as good as aluminum is stretching it pretty far. 7075 aluminum has the tinsel strength of steel. I don't think the same can be said about polymer.

I'm not completely against getting and using one of the 80% polymer lowers but I think I'll wait a little bit or until I see a torture test of one firing at least 10,000 rounds. It would be a neat little project and most likely I'd do a dedicated .22 build with it.

Bottom line though. If you have two AR's set up exactly the same except one has a polymer lower and the other has an aluminum lower. If you could only grab one in a SHTF scenario, which one are you going to sling over your shoulder?

 

[regulator]

I have a Bushmaster M4 Carbon with less than 500 rounds through it. It cracked above the take down pin diagonally from the buffer tube almost through to the pistol grip. Not all the way but almost. I was a big fan of them until I saw that, so all I can say is form your own opinion and buyer beware

 

[Sampson]

Thanks for some personal experience info. That'll help me make my choice.

 

[wesser1]

I own one poly lower and many metal lowers. With the price or blemished metal lowers dropping back to normal, you are probably best to just go with what is proven since price isn't a huge factor.

 

[alpine44]

I use a NFA polymer lower on a 300BLK pistol build. The gas system is configured for subsonic rounds so the buffer slams home pretty hard when shooting supersonic loads. After about 1000 supersonic rounds and a few hundred subsonics the NFA lower looks and fits like when it was new.

I would not use a polymer lower for a gun I plan to bash in doors with but they seem to be stronger than what one would expect from "plastic".

One advantageof the NFA lowers is that they lock up very snugly on any upper unlike the aluminum lowers that seem to get looser and looser tolerances over the years. I have an old (ca. 1995) Bushaster lower that fits decently on most uppers but the Spikes I bought just before last year's craze are rattle traps without a wedge, etc.

 

[zombiehunter]

*snip*

Bottom line though. If you have two AR's set up exactly the same except one has a polymer lower and the other has an aluminum lower. If you could only grab one in a SHTF scenario, which one are you going to sling over your shoulder?

How far do I have to carry it? (trick question, I'd take my PLR-16 lol)

 

[ObsceneJesster]

I use a NFA polymer lower on a 300BLK pistol build. The gas system is configured for subsonic rounds so the buffer slams home pretty hard when shooting supersonic loads. After about 1000 supersonic rounds and a few hundred subsonics the NFA lower looks and fits like when it was new.

I would not use a polymer lower for a gun I plan to bash in doors with but they seem to be stronger than what one would expect from "plastic".

One advantageof the NFA lowers is that they lock up very snugly on any upper unlike the aluminum lowers that seem to get looser and looser tolerances over the years. I have an old (ca. 1995) Bushaster lower that fits decently on most uppers but the Spikes I bought just before last year's craze are rattle traps without a wedge, etc.

Were the Spikes lowers loose when you first attached your upper or did the just get loose over time? Not that it would matter being how it has no effect on accuracy or reliability. I know it does bother some. I'm just curious if they were loose from the start.

Sent from my SGH-T999 using Tapatalk 2

 

[yellowsled]

I have tried a few uppers, Colt and PSA on NFA lowers and I agree, its a nice tight fit.

 

[comecamping]

Frontier Arms has a torture test video with their lowers