Polymer 80 Build Tips (9 Hidden Tricks)

Building a Polymer 80 is a fun and rewarding experience. 3D gun builder covers the best-hidden Polymer 80 build tips and tricks to successfully complete your first build.

From failures to fire to failures (FTF) to eject (FTE), there could be a lot of issues if you mess up simple details on your Polymer 80.

polymer 80 build tips tricks

After building over 200 P80 handguns, we have found some tips to guarantee first-time quality polymer 80 builds.

Keep reading to find out 3D gun builders 9 best Polymer 80 tips for the perfect build (also check out the new Geisler Defence 80% 19x, we cover the product and offer build tips to get you going).

Do your Research

Doing your research before beginning your polymer 80 build is the best way to ensure success. There are thousands of resources on the Internet, from YouTube to Reddit to the polymer 80 manufacturers’ website, to find out exactly how to build, assemble and test your Polymer 80.

p80 tip do your research

3D gun builder also has an extensive section covering Polymer 80 guides tutorials, and product reviews.

Asking questions is also essential whether online on Reddit or with a friend with more Be gunsmithing experience than yourself; never be afraid to ask.

End Snips / Fret Cutters for the Tabs

Removing the tabs on the rear of the polymer 80 frames can be a severe pain a**. Often people use Dremel tools, files, and sandpaper, which can be highly time-consuming.

p80 tip end snips for tabs

A trick that will save you several hours on your polymer 80 build is purchasing a pair of end snips from Home Depot or Amazon. 

You can snip the tab close to the base but just above it to not go too low, and boom, your tab is gone.

Of course, you will need to go back and sand with increasing sandpaper grit to get the real smooth, but this is the best tip I have found to make building a polymer 80 less painful.

Polymer 80 Channel Removal

Removing the center channel from your polymer 80 frames is one of the most complex parts of completing an 80% bill. Getting into the space and using tools takes a lot of work.

p80 tip channel liner removal

The best way to remove the channel from the polymer 80 is to start with an X-Acto knife, removing triangles of the polymer as you work your way down to the base of the frame. Once close, you can use a file to remove the hard edges and more significant pieces of polymer.

To finish, we wrap a pencil or drill punch with sandpaper and run it back and forth until the channel is smooth out and deep enough all the way around.

Again, you finish this by slowly increasing sandpaper grit until you have a small factory-finished look.

Drilling the P80 Pin Holes

Drilling the pin holes on your polymer 80 frames (Check out our in-stock P80 drill jigs) is one of the quickest parts of building an 80% firearm.

p80 tip drilling pin holes

While this seems straightforward, Drilling incorrectly or slightly off-center could make the functioning and rest of your polymer 80 build poor quality. Ensuring you are drilling straight, centered, and accurate pin holes for the rear rail and locking the back walk is essential for building a functional P 80.

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Make sure your polymer 80 is secured tightly in the drilling jig place the jig on a flat surface and only use a handrail to drill the hole. Also, as recommended by the manufacturer, do not drill through to the other side. Do one side of the polymer 80 at a time.

3D gun builder produces and sells a polymer 80 drill jig that helps to align the drill, bit, and hole for the best possible end product functioning of your gun

Installing Polymer 80 Lower Parts Kit

Sometimes you will be lucky, and the lower parts kit will install on your P80 frame without issue. 

p80 tip lpk install

However, often you will face some resistance weather with the pins, locking lock, or front and rear rails. Force is usually required to see everything well; there is a balance, though, as you want to avoid damaging your polymer 80 frames before installing the lower parts kit. 

Do you want to have all the necessary tools? A drill punch, armors, hammer, and needle nose pliers will be all you need to install your P80 lower parts kit. 

The pins sometimes will need to be angled slightly and then lightly hammered to sit into place when going across the trigger group through the rear rails or even the front pen into the locking block.

You will use the needle nose pliers to remove the pins if you need to start over at any point or during tape down until your polymer 80 is worn in.

Polymer 80 Slide Kit Installation

Most polymer 80 builders will buy the upper for their Glock subcompact, compact, or full-size in a kit. These often come preassembled from the manufacturer, making this part of the build quite simple. You will want to apply a drop of gun lube to the front rail, rear rail, trigger housing, and slide. 

p80 tip slide kit installation

You will, however, want to be sure to do everything correctly. A lot of dirt and debris can get stuck in the polymer 80, making the slide action difficult to fully clean and remove any polymer debris or pieces before installing and lube in the slide.

No. At first, it may be difficult to fully seat and rack your slide. You will want to manually rack the slide several hundred times to wear it in pieces and get the fit just right.

Live fire is the other method we prefer for breaking in a new polymer 80 build. Even if everything fits poorly or action right, live fire will often force the components into the correct place. 

Break-in happens somewhere around 200 rounds also. When live firing, your polymer 80 makes it easier to spot where the actual issues lie.

Fixing Failure to Eject Tips

There are two common issues relating to fixing issues to inject with your polymer 80 handgun. The first issue often associated with failure to eject on a P80 is the aftermarket ejector.

failure to eject polymer 80

Often purchasing a Glock GEN three OEM injector can fix this issue and help to push the slide casing out of the side of the pistol. 

The second issue is that your slide cannot move all the way back, trapping the casing in the gun. This is often a case of your rails rubbing against the slide.

Remove the slide and continue to sand and bring down the top portion of your polymer 80 frames so the slide can action more quickly. The third tip would be to keep live firing and testing your polymer 80. often this issue can be fixed after the break-in. Period

Slide Lock Spring Issues

The other common problem we have seen and experienced is the slide lock spring, catching the slide, or holding the slide back when the magazine is not empty. 

p80 tip slide lock spring fix

This is, again, often an issue with aftermarket parts using the incorrect generation of slide lock spring for your polymer 80. 

Often you can see if it’s holding too tight or too loose. You can remove the polymer 80 slide lock spring and bend it up or down depending on if you need more attention or less tension on the slide locking mechanism.

Bonus Tip: Do your Research Again

Well, this may seem redundant. Doing your research is one of the most critical parts of building a polymer 80. 

p80 tip do your research again

Some slides work great with the polymer 80, while others cause many issues. Pricing is only sometimes a factor or indicator of quality.

You will want to look at specific YouTube video subreddits, or any information about which slide parts kits and accessories work best on the polymer 80.

While the polymer 80 is modeled after the Glock in GEN three, there are some specific differences in both the generations, style and grip, and overall frame that can cause compatibility issues we have found very solid and cost.

3D Gun Builder’s Glock complete slide kits work great out of the box and have very few issues down the road.


We hope you have enjoyed and learned something from our Polymer 80 build tips and tricks Article. 

Whether this is your first P80 build or number 100, there are always more tips, tricks, and for-see issues to discover when building 80% guns. 

If you have any questions or know of any great Polymer 80 build tips that would be helpful for other P80 builders, please leave a comment below.

Written By

Dan M.
Latest posts by Dan M. (see all)
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