Many have asked about the closed bolt conversions for the MINI Uzi. These pictures will hopefully illustrate the differences. I bought a complete FA IMI MINI Uzi Closed bolt setup from Vector in 2001. Here is a picture of the right side of both a SEMI and FA closed bolt. Note how the ejection port on the FA is smaller. Also note that there is no sear relief on the right side of the bolt as there is no right side of a FA MINI closed bolt sear. This is kind of strange as to why their is a sear relief on the SEMI bolt as the SEMI sears in the MINI Carbine’s also had no right side sear pad either.
right

This picture shows the differences between the Semi and FA bolts. 1. The FA bolt has the lower rim at the bottom of the bolt while the Semi does not. Trying to use the Semi bolt without the lower rim in FA will usually result in light primer strikes. 2. The Semi extractor’s claw is not symmetrical. The FA extractor has a larger gripping surface.
front

Another picture showing the existance of the lower rim on the FA bolt vs the lack of the rim on the Semi.
bottom

Looking at the left side of the bolts shows that the firing pin safety trip is slightly different. They are so slightly different that I believe that they are interchangeable.
left

Looking from the rear, there is not much difference. You can again see the relief on the right side of the SEMI bolt.
rear

The striker assembly is the same as the SEMI.
striker

The FA OPEN and CLOSED bolt assemblies side by side. Note the difference in ejection ports.
open_closed_right

open_closed_top