Has anyone matched the KP-9 POLYMER MIL-SPEC FCG RECEIVER with a PSA GEN4 16" 9MM?? That sounds like a fun Range gun to me that could be put together with Irons for sub $700 or near that with a Red Dot.
Polymer lowers have an extremely high chance of breaking. I wont use one with 5.56, and i sure wouldnt use one with blowback 9mm.
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Well things advance, I forget but I think KE tested their POLYMER MIL-SPEC FCG RECEIVER out to Thousands of rounds including a lot of full auto. if memory serves me right. KE Arms KP-9 - YouTube
It’s like $260 for the Mil Spec so I’m not dumping a heap of cash, and people said the same things about POLYMER Pistols In my youth, I think they still make one . . . .Glock or something. . . .I think they handle 9mm ok.
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A polymer pistol like a glock functions very differently than an AR-9.
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Agreed, and the KP-9 POLYMER MIL-SPEC FCG RECEIVER is arguably at/near the edge of Polymer technology. . . . as was Glock in ?? 1978 even through 84 maybe.
So the risk load for lower failure IS higher then with an aluminum 9mm lower from a respected manufacturer. But It’s the lower not the upper so it’s mostly a $260 risk not so much my life (I’m old and well insured anyway)
So I’ll take your thoughts under advisement. . . and order one anyway.
I’ll post how things go from time to time. . . .or you know, have my widow post once if things go bad 
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Good luck. Polymer AR lowers generally crack at/near the rear take down pin and beavertail area. Keep your eyes open.
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Nothin’ a li’l Superglue can’t fix-up, Good as New!
(if a single drop will glue your Supervisor to an I-Beam by his Hardhat - should hold a gun together NP!)
I find that highly unlikely to happen on the KE Arms lowers since the point of failure on most polymer lowers is the threading for the buffer tube, which is not present on their lowers due to the integrated stock.
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Or you know the warranty
The KP-9 has a lifetime warranty for normal use.
Sling Attachment points wearing out is not grounds for a receiver replacement.
If the receiver breaks through misuse or neglect, we will replace it ONCE for $65.00.Structural modifications including stock shortening and removal of material and dyeing the receiver void the warranty.
It seems sketchy to me that they have to say “if it breaks we will replace it once for $65”. For $65 i have a new aluminum lower.
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That’s not what they say, read it again.
and also
So in addition to a lifetime warranty for normal use they will also replace it ONCE for $65.00. If the receiver breaks through misuse or neglect
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Well maybe I will make it a bit of a Diary, I’ll have both the KP-15 & KP-9 lowers and I’ll try to keep you all up to date. I know, I know the range time will be such a burden to me when I could be home doing chores, But these are the kinds of sacrifices I’m willing to make for you guys. 
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I hope you realize im trying to hopefully save you headache. I truly hope you dont need their warranty, but one more question…who gets to define “normal use?”. You, or them? Just something to think about.
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No I get it, this is innovation, and that entails risk.
It’s just funny to me because So many young people I shoot with think I’m a bit of a fudd because of my Wood stock Squad Scout and my love for old bolt guns & .303 brit
Now here I am defending my interest in cutting edge POLYMER 
I think this makes me a renaissance man , or just a little odd.
I can spell Odd. . . . . .we’ll go with Odd
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SWEET! Looking forward to it. KE products look very innovative. I am interested to see what you put together.
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Actually - I Tease.
If I were to obtain any poly lower, it would be the KE - I am familiar with the engineering that went into it, and have nominally followed its story up to the current Lawsuit-kerfluffle currently surrounding the lowers.
Ian sort of sorts-out the suit here:
And apparently it’s not going all that well:
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I had almost forgotten - Brownells is involved heavily with their “WWSD2020” Project, and has an information page on the progression of the Development, if anyone cares to read and watch some of the videos:
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Yeah, I saw that. I am going to buy a $25 patch.
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I’m unqualified to speak on the lawsuit, having heard just the one side. I hope it works out. Lots of people sue and get sued good and bad. I hope it turns out KE IS what they seem to be.
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Well here we go! I got the PSA Upper KE Arms Lower and Brownells PPC spring & Buffer
My Red dot is shipped, also from PSA (I hope there’s a decal with it 
I didn’t get one with my Upper)
I’ve got a LOT of irons in the fire, but I’ll try to update when I get this together and out to the range.
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