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.