The 80% Easy Peasy EP lower.

[WestKentucky]

I recently tried my hand at an aluminum 80% and things did not go well...in fact they still aren't going well with that lower. Another member here made sure that I got my hands on an EP poly 80%. To say that the EP went better is a gross understatement. In fact the only problem I had was a dull drill bit from the aluminum lower. I got home and started pulling stuff together about 5 o clock this afternoon and at 6 I was back inside rinsing the finished lower off in the sink to get the crud off of it.

I know a lot of folks don't want to fool with poly, but they have proven themselves worthy enough. I see no reason that this lower will not serve me well for years provided I don't use it as a sledgehammer.

So here's my comparison.

Aluminum:
Costs...
114 for matched upper/80% lower. Call the lower half at 57 bucks I guess.
4 broken drill bits so add 10 bucks
47 dollars for the replacement short flute end mill I destroyed
A decent 1/4" mil bit the dust cutting out the broken drill bits, another 10.
Total:124 dollars...so far.
Impression:
Words allowed on THR do not adequately describe my frustration. It was a terrible experience that won't happen again.
Time: I'm at about 6 hours on it and I'm now waiting for the specialty endmill to come in to finish it up. I guess I will have 2 or 3 more hours in it.

EP poly lower
Costs...
EP had these on sale for 29 bucks plus shipping. Normally a bit more, but 50 is a safe estimate after shipping.
Nothing broken, damaged etc...
Total should be about 50 at normal price, less if bought on sale.
Impression...
Smooth, enjoyable, and pleasant. I have a sense of accomplishment after fighting the aluminum lower and then breezing through this one. The lower would only fit the Broken Arms jig after a slight cut to the front takedown pin area which was binding on the clamshell screw.
Time:
almost exactly 1 hour... But only if you count the time to drag out the drill bits and then sweep up when finished. To be fair I used a short fluted 1/4" endmill and just hogged material the depth of the flutes and ran it in the Broken Arms jig with plates 4 and 5. Anybody with a rigid drill press could do the same thing. The only advantage I had was bit speed in my mill. For a drill press I would guess you would add about 5 more minutes to the cutting portion, or if you used a full length fluted mill you could possibly do it faster than I did.

Pictures of my handywork are attached below...it went so quick and easy I didn't even think to take any during the process. This is right after its bath in the kitchen sink.

 

[mjsdwash]

were you by any chance using those garbage titanium nitride drill bits? they don't even cut hard wood, just make it smoke. Ive never had a problem using any brand carbide drill bits, in metal much harder than aluminum.

 

[WestKentucky]

I was using some bits that were loose in my toolbox. I'm 99% sure they were decent bits from unknown manufacturer...but there is possibility of them being random junkers. I replaced them with cheapo Dewalt bits from Lowes and they cut right through, but I did break one more due to deflection when I sneezed. Can't blame the equipment for that one.

 

[mjsdwash]

the titanium bits are gold colored. at least you got what you were after. Theres a company making injection mold kits with reinforcing braces now for lower now, if this is something you plan to do in the future

 

[Acera]

Have you tried a Polymer80 kit? It comes complete with the jig, bits, etc. for about $80.



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[WestKentucky]

Have you tried a Polymer80 kit? It comes complete with the jig, bits, etc. for about $80.



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No, I got my feet wet on the aluminum, then got going on the poly. I finished the aluminum last night after work since the new endmill showed up. Nothing else damaged or broken, and about 2 more hours of fighting it to yield an ugly, scratched and scuffed lower. It will get a spray can touch up.

 

[Acera]

Thanks.

Got a couple of them I am waiting on cutting on.

Had a bad experience with one of the polymers. Chuck fell out of the press and puched an extra hole in the bottom, it will assemble but looks bad

(Good news is I have what the BATFE considers an 'AR-15' with no serial number (think scary assault weapon) for the next gun buy back they have in the area.............yeah, I plan on making money, LOL.



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[dogmush]

I've got a couple of poly 80% lowers. A polymer 80, had an EP*, and 3 James Madison Tactical's.

For my time, the JMT's are one of the nicer poly lowers out there. They beef up the buffer attachment and front pivot pin, their poly machines well with little to no flash, and nice round holes, their included Jig is nicer then Polymer 80's. You do need your own tooling, where Polymer 80 sends you some cheap end mills.

*I broke the EP right at the rear take down pin, but I was testing to destruction to see what it could take. But I don't have pics of it.

** I have a mill, and have also machined aluminum lowers. For my time, effort, and tooling I actually prefer the poly lowers (as long as they have been beefed up appropriately). It also saves me a step on anodizing and/or spraying the inside of the aluminum lowers.

JMT's:



Polymer 80: