Discussion in 'Rifle Country' started by Rem.222, Jan 13, 2014.
It is not with out its problems. The WHOLE FTG is plastic. The hammer seems to work fine. The mag release seems iffy.
The trigger is my only real complaint. Since it is plastic also and may get pulled hard in times of distress... well it has a good bit of deflection which I don't care for. But, the tigger pull is light and breaks cleaner than most factory triggers.
I've owned 2 poly lowers: ATI/Omni complete lower, and a M&P15-22 rifle.
IMO they're ok for light duty and plinking only, including hunting if you must. Don't throw it around or abuse it though.
I have been around two different kinds of these newer polymer lowers. I purchased two of the EP Lowers and found they liked a lot to be desired in fitment to three different uppers I tried them on. The take down pins were off center from the hole not allowing the pin to go in and also the distance to the matting surfaces between the two receivers were way off and would cock the lower at an angle. This was also due to the take down pin locations being off. The gap between the two receivers should be a maximum of about .020, (.030 was allowed in my military days), on a good fit these and the replacements I eventually was sent out measured .020 - .025 in the rear and .028- .035 in the front putting them at an angle and such will stress the rear buffer tube area as it puts it at an angle for the bolt carrier group to hit against the buffer. After four have been sent my way to replace the defective one's only one has come out in specs, so my opinion of the EP Lowers is stay away from it as your just going to be playing mail tag with finally getting one that fits like its suppose to! Most of the polymer lowers seem to be thicker in the front take down pin area and the buffer tube area which would be your areas of concern but remember most of the stress in firing an AR on the lower is in the moving mass of the BCG and it is absorbed by the spring and buffer then sent forward again into battery. The polymer lowers in my two cents are good candidates for an adjustable gas block, light BCG's, buffers etc.... to set the firearm up for minimum recoil and thus reduced stress all around! Like was stated earlier if your not abusive to them I don't think you'll run into any problems I would rate their strength on par or above the cheap cast aluminum lowers, plus the polymer will have some give in it where cast aluminum is a bit brittle especially when cold and I've seen several of those broken in the buffer tube area!
NOTE: the one I have is definitely a commercial buffer tube. That might explain why it feels 'tight' mated to my Colt upper.
I did buy 2 stripped NFA lowers.
The two stipped lowers ended up with CMMG parts kits, I had to use a needle file to get a couple of the pieces to fit right, they were just a little too tight on the lower. It's been a while since I messed with them, but I believe it was the mag catch and the safey holes that needed just a little bit of material removed. It wasn't enough to be of much concern.
One lower that I completed with the CMMG lpk ended up with an 18" DPMS M12 barrel and DSArms uppper.
The other ended up in the junk box for a later build.
I took the completed rifle out, fired it a few dozen times, and brought it home. It sat in the cabinet for about 2 weeks and I took it out again.
The second trip out I had brought 10 full 20rd mags to run through it and get the scope zero'd and all that jazz.
The third mag in, I fired a round and the buffer tube and stock broke away from the gun.
The rounds were factory LC rounds.
There is a mold mark on top of the ring where the buffer tube screws in on the NFA lower, my lower cracked across almost perfectly in the mold mark.
I called the dealer that I bought them from and explained to him what had happened and I wound up returning those to him for a refund and bought Stag lowers to put my parts kits in.
I called NFA and told them what happened and they seemed more than willing to oblige. The dealer was local though and willing to make things right without me having to ship the lower back to NFA.
I'm not saying the poly lowers are bad, I think I just got one that was flawed. I just got turned off at the thought of sticking a polymer lower on any of my rifles after that one broke.
For a casual shooter that just wants an ar15 to have one, they'd probably be fine, but if you're wanting a knockaround rifle, I'd invest in a metal lower.
With Aluminum lowers frequently on sale for $50, it seems like a false economy. An aluminum lower is expected to last a lifetime or more. This thing will last until it gets dropped and cracked. That could also be a lifetime...or next week. For most users, lightly plinking a few rds per month at the range, they won't notice.
There are models coming out with metal reinforcing the critical areas, I'd consider one of those or the Cavarms with built in stock.
And before the inevitable comparisons to other polymer firearms start coming in...those were all engineered with polymer in mind as the material from the beginning. And most are also metal-reinforced in critical areas. Taking a to-spec AR lower designed for aluminum and substituting polymer is the problem. Too weak in certain areas, particularly where the receiver extension threads in.
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