How To Install a Polymer80 or Glock FIring Pin Channel Liner

When you buy a stripped slide for your Glock or Polymer80 build, you will find that you need to install a Firing Pin Channel Liner – Glock part number 1148. For some reason this worries a lot of folks but it is actually extremely easy to install.

This small plastic tube is the firing pin channel liner. Please note it is solid – the tube with a channel in it is the firing pin spacer sleeve so don’t confuse the two. Also, please note this has two different ends – the left end is beveled and is what goes into the slide. The right side has a straight edge and this is what will rest on the shoulder of the installation tool.

Do I really need it?

This question pops up from guys who feel intimidated by having to install the liner. The short answer is, “Yes, you do really need it”. The liner serves a couple of purposes. First, it is a buffer that isolates the firing pin from the steel slide so you do not have metal on metal wear. Second, because the system was designed with that spacer, leaving it out will cause alignment problems. Note, stick with OEM Glock plastic liners. I’m not recommending brass, stainless, etc.

Do I need a tool?

I’d recommend it and they are dirt cheap. Basically the tools are a metal rod with a shoulder. The channel liner slides on and you tap it into place. Some are threaded to enable removal. I use the following simple tool for installation:

Ok, how do I install the liner?

The first step is to inspect the channel liner. On the end with the straight cut you will usually see some waste plastic, known as “sprue”, left over from the casting process. Use a razor blade or sharp knife and just cut that off so it doesn’t hang on anything or get in the way.

See that little piece of waste plastic sticking out on the top? Just cut it off flush with a razor or a sharp knife. You cal also see how this is the straight end of the liner that will sit against the shoulder of the installation tool.
This photo isn’t as crisp but hopefully you can see the slight bevel on this end of the liner. This is the end that will go into the slide.

Slide the liner onto the tool. The straight cut edge rests on the shoulder of your tool.

Slide the liner onto the tool with the bevel facing out and the straight edge against the shoulder.

Then you insert the liner into the big hole in the rear of the slide. You and usually push it a bit of the way. Rest the nose of the slide on your bench and tap lightly with a small hammer. You will hear and feel the difference when the liner is seated all the way. It really is that easy.

This is just so you can see the orientation of the tool. I rest the nose of the slide on my bench block and tap the tool with the a small ball peen hammer to seat the liner. I had to use the vise purely to take the photo.

A Video To Help

Brownells put together a real nice to-the-point video on how to do this:

Sources For Liners and Tools


The Glock firing pin channel liner is definitely nothing to fear and I hope this helps you out.



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