FN FiveseveN Forums - Detailed dissassembly

Posted by RobR:

FN FiveseveN Forums - Detailed dissassembly: "Detailed dissassembly



I couldn't resist the urge to improve the trigger so I took my USG apart last night
Here's how:

1. Remove fire control module- It is held in place by the second pin from the rear of the pistol. To remove the pin gently lift on on retaining/slide release spring with a credit card something else very thin and push the pin out from right to left. Pull the module up and out out, very little force is required.

2. Note the relationship of the sear and firing pin safety spring. Release tension from FPS spring and remove. Lift out FPS lever. Lift/remove sear pin, sear and spring will slide out of bottom of module.

3. Remove hammer by releasing tension(use your fingernail) on spring and removing the small pin it rests on. Remove hammer pin and spring.

It should take about five minutes.

Reassemble in reverse order. NOTE. when re inserting the module into the frame be sure the sear pin spring engages the frame properly or you will not have spring tension on the sear(you can guess how I figured that out!) You should feel the spring tension when re inserting the module.

This pistol is very easy to strip and assemble. Alot easier than the Sigs or USP I worked on.

I polished just the sear/hammer engagement.
Before- 5.3 lbs gritty
After- 4.6 lbs very smooth
Note I wrote polish- DO NOT REMOVE METAL.

I'll go back and polish all of the mating surfaces tonight. I'm expecting about a 4lb pull that is super smooth.

Hope this helps anyone who's interested
Rob"