Assembling an UZI Lower

The magazine release and magazine release spring are the first parts to be assembled to the lower. The spring has a side with a loop and a side with the two ends of the spring. The side with the two ends of the spring should go up against the magazine release.

Attach the magazine release to the grip frame using the magazine release pin (the smallest pin on the lower).

Insert the selector switch spring into the two small grooves in the left side of the magazine well.

The selector switch, full auto (select fire). This one is made to work with a bolt safety.

Install the selector switch at a slight angle as pictured, toward the front of the hole. This allows for the button to be attached.

Slip on the button, push down on the selector and pull to the rear. Insert the grip safety from the top with the plastic part forward in the hole. Drop the trigger into the trigger hole from the top. Put the grip safety spring in the two notches for the spring (one on the grip safety and the other in the grip frame).

The trigger spring (also bolt safety spring if bolt safety is present).

From the top you can see the way the trigger spring should look just after installing the trigger pivot pin (the shorter of the two pins with the screwdriver slot). You will flip the two spring ends down around the trigger mechanism after the pin is inserted. The slot on the pin should be straight up and down as it is inserted and the slot should be on the right side of the lower assembly. It should be inserted from the right side also.

The bolt safety (an option). If you have a bolt safety, it should be installed along with the trigger so it uses the same pin as a pivot point. As the pivot pin is inserted, the grip safety should be fully to the rear and sitting all the way down inside the lower. The small flat notches in the pivot pin should be facing downward.

If you have a bolt safety, ensure the selector is in the safe position. This will keep the spring tension at it lowest possible while you "load" the trigger spring. Pictured is a small pocket screwdriver that I cut a small notch in to help with this task. Be careful or you'll end up with a pin sized puncture in a finger tip (OOUUUUCCCHHHHHH!). Load the right side first, then the left side (mostly just to keep the tension lower as you do it).

After this step is done, if you have the bolt safety, place the selector in the semi position. Remember to push down on the bolt safety as you do this.

The sear and sear spring. A semi auto sear is only slightly different.

The sear with sear spring attached via the two ends of the spring inserted in their intended holes in the sear.

A side view with the front end of the sear at the top of the picture. Ensure the spring looks the same as pictured.

The sear pivot pin is inserted from the right side with the screwdriver slot on the right side same as the trigger pivot pin. The flat spots on the pin also face downward. The grip safety must be fully rearward (the spring should be keeping it there anyway). First to get the sear in place, slide it rear end in first, up under the trigger assembly. Push it rearward enough to allow you to bend the spring loop forward and down to catch the front of the lower. Insert the pin through the right side of the sear and sear spring. then through the disconnector stop, and on through the left side of the sear and spring. Once this is done, push the grip safety forward to ensure it will ride into the groove in the sear pin.

While holding the grip safety forward, install the grip panels.

When you reach this step, hopefully your lower looks like this. If it doesn't, start over.