P80 Kit

An 80% lower lets you build a pistol without serialization or FFL paperwork—if you’re willing to put in the work. Polymer80’s P80 kits are the gold standard for DIY pistol builds, with reinforced nylon frames that handle recoil better than cheap knockoffs. These aren’t “toys”; they’re for builders who understand fitment and want a factory-spec Glock or Sig clone. The jig-and-drill process takes patience, but you’ll end up with a pistol that’s truly yours.

What’s in a P80 build kit
Frame-only kits include the 80% lower, jig, and drill bits—you source the LPK, slide, and barrel. Complete kits add everything but the slide (LPK, rails, mag catch). Either way, you’ll need a Dremel for cleanup and calipers to check depth. Pro tip: Buy a spare locking block (G17/G19 kits sometimes need fitting). Avoid “bargain” rails; P80’s stainless steel front/rear units are worth the extra $20.

Choosing the right frame
Match your frame to your slide: PF940C for Gen3 G19 (compact), PF940V2 for G17 (full-size), PF940SC for G26 (subcompact). Big-bore builders want the PF45 (.45 ACP G21). The PF9SS fits G43 single-stacks, while the PF320PTEX clones Sig’s P320. Stick to Gen3 Glock parts—Gen4/5 need adapter kits. Desert carriers prefer the PF940V2’s grip length for all-day concealment, but the PF940C hides easier in AZ heat.

Legal status
As of 2025, federal law still allows 80% builds for personal use (no resale), but ATF Rule 2021R-05F requires serialization if selling. State laws vary: CA, NY, NJ, WA, RI, HI, NV, OR, CO, and DE ban or restrict them. We ship to non-restricted states only. Verify your local laws—especially if building a P320 clone (Sig’s legal team hates these).

Building tips for first-timers
Go slow with the drill press—polymer grabs bits. Use the end mill for the recoil spring channel, then break all edges with 400-grit. Dry-fit the slide before pinning; tight rails mean you’ll need to lap them. Common mistakes: over-drilling pin holes (measure twice), skipping deburr (causes cracks), or forcing the trigger housing (it seats flush when done right). A vise and punch set beat a hammer and prayer.