My Polymer 80 build

[NETim]

Midway had "Glock"P80 lowers on sale. I had a gift certificate. So I bought one.

Even with my moderate gunsmithing abilities, it wasn't very difficult to assemble. I used the infamous Dremel tool to grind down the various places on the lower required to complete the project. Dremel for the rough work, various files for the finish work.

The front locking block was somewhat difficult to seat in the lower. Poly80 recommends using a 7/16" diameter rod, such as the shaft from a 4 way screwdriver, wedged into the trigger opening to spread the lower so that the block can be seated. I used a Sharpie marker (the cap end) seated in the lower by tapping it with a hammer as far as the Sharpie could go. I also broke the edges of the block with a file. It then seated through the judicious use of a light plastic faced hammer. The block MUST be square to the lower to seat. It's tight.

I used Glock OEM lower parts. They installed as one would expect. I preemptively junked the 336 ejector in favor of the 30274 from a gen4 trigger housing.

The slide (borrowed from an existing Gen3 G17 in the vault) rode the rails smoothly until I pinned both blocks. After installing the pins, there was major binding as the slide engaged the rear rails. Filing and stoning on the rear rails was required to get the slide to move freely and go into battery reliably.

Initially the trigger wouldn't travel far enough forward to engage the trigger safety tab on the lower, but a little manipulation corrected that situation quickly.

First range trip I fired 150 rounds through it. (Dot torture primarily). It ran flawlessly until late in the test when it failed to feed after seating a mag. Then I got it to feed after re-racking a few times but then the slide didn't lock back. It was then I noticed the trigger pin had drifted to the right about 1/8". I drifted th pin back in and it started running correctly again. Variety of ammo was run. Mostly 115 FMJ.

The slide bites me on occasion, just like G3 Glocks do.

The lower was finished well. There was a slight seam on the underside of the rear of the lower/beavertail extension area that was easily taken care of with a little 220 sandpaper.

I like it. The gun appears to work well although I have hardly tested it. I'm concerned about the drifting trigger pin. Only time will tell if that's going to be an ongoing problem. I have a G3 slide on the way for it.

I'm not sure what role this thing will serve. I guess I just wanted to build it because I could. It was a fun project if nothing else.

[BillSWPA]

Good to know. I have considered trying one of these builds. Thanks for posting.



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[MDFA]

I undercut the trigger guard and reshaped it. Vickers slide and magazine releases and a Vickers flat trigger. I found the Poly 80 frames point better for me than a stock Glock frame.

[NETim]

I undercut the trigger guard and reshaped it. Vickers slide and magazine releases and a Vickers flat trigger. I found the Poly 80 frames point better for me than a stock Glock frame.

I prefer the grip angle of the P80 to the Glock as well. I may eventually change out the trigger shoe too. I rounded the edges of the OEM mag release. As a lefty, I knew those sharp edges would become an issue.

Thanks!

[NETim]

The trigger pin walks out to the right of the frame when firing my project P80. I've tried two different slide stops and two different trigger pins with the same results. My understanding the slide stop is what retains the pin in Glocks.

The folks at Poly 80 are going to warrantee the frame and send me a new one. (After I cut the frame in half and send them a verification pic.)

They hint that I didn't drill the holes right. They lined up. I was careful to drill at right angles to the frame.

I don't hold out much hope of the new frame performing any better frankly. I don't know what I'll do differently when attempt No. 2 begins.

At least they're trying to work with me.

A lot of work down the drain.

It was a fun project though.

[awp_101]

The holes didn't line up on the G19/Compact frame I did last year. Almost had to pound the pins in and the trigger pin holes were far enough out of spec to cause binding on the trigger. Didn't bother with attempting to use the warranty, I sold off the top end I put together and gave the rest of the parts to the youngest boy as spares for his G19.

I sort of expected to have issues when I saw the instructions said to drill the holes with a hand drill instead of a drill press. Now that I have a small vertical mill I might try another if I can get the frame dirt cheap and I'll drill the holes with a press, instructions be damned...

[SiriusBlunder]

if I can get the frame dirt cheap and I'll drill the holes with a press, instructions be damned...

FYI: Midway has the older compact and sub-compact frames on closeout for $74.99 right now.

Compact:
https://www.midwayusa.com/product/10...-23-32-polymer

Sub-compact:
https://www.midwayusa.com/product/87...-26-27-polymer

Free shipping on orders over $49.

[HCM]

The holes didn't line up on the G19/Compact frame I did last year. Almost had to pound the pins in and the trigger pin holes were far enough out of spec to cause binding on the trigger. Didn't bother with attempting to use the warranty, I sold off the top end I put together and gave the rest of the parts to the youngest boy as spares for his G19.

I sort of expected to have issues when I saw the instructions said to drill the holes with a hand drill instead of a drill press. Now that I have a small vertical mill I might try another if I can get the frame dirt cheap and I'll drill the holes with a press, instructions be damned...

Do they say why the don’t recommend the drill press ?

[awp_101]

FYI: Midway has the older compact and sub-compact frames on closeout for $74.99 right now.

Still too much. I'd be a player at $50, maybe.

Do they say why the don’t recommend the drill press ?

I don't recall anything specific other than they recommended a hand drill over a press, nothing about the why. I've seen reviews from early on that indicate when you have a problem, it's almost always "you drilled it wrong" with the rare admission of "maybe it's a misaligned jig".

I'm aware of one custom builder that either uses these or the Lone Wolf frames but I don't know if he's using the 80% frames or not. Come to think of it, I didn't see any frames available at LWD last time I looked so I don't know if they are still offering DiY frames or not.

[NPV]

I had issues with a Brownell's exclusive P80 I got last year, the rear pin held the rear rail up too far making the slide sluggish. They sent me a new frame and I have issues with the trigger bar contacting a section of the rear rail.

All in all I wish it would work as I really like the way the frame feels in my hand. I will break it out at some point to see if I can resolve the issue (moth balled it to spend more money on 1911s).

Moral of the story; sometimes when something seems too easy it may be too good to be true.