RoverDave
12-10-2006, 04:43 PM
Barrelxchange asked me to try out a .380 conversion for the Mini UZI. It took a little bit of fiddling around but I got it running today. Initially barrelxchange sent me a barrel and magazine. I used a standard 9mm open bolt with a modified extractor. I filed down the "bump" on the extractor so the claw would sit a little closer to the center of the bolt face due to the smaller rim of the .380. My initial tests showed that the .380 was just too weak to cycle the standard UZI bolt, even when I tried a lighter spring.
Barrelxchange then sent me a lighter bolt. He used one of his 9mm heavy bolts and made an aluminum top to it instead of tungsten. The internal holes were left empty instead of inserting the tungsten cylinders. I tried that bolt with a standard Mini UZI spring and it still was not ejecting strong enough to be reliable, however when I switched to a weaker spring, the setup ran 100%. The spring I used was the spring from a full size UZI. I cut off the forward end of the guide rod so I could remove the spring and then cut the spring so the free length (uncompressed) was 8".
It proved to be a lot of fun to shoot. With that spring and bolt it had a pretty slow ROF. Plus the light recoil of the .380 made it easy to keep the gun dead steady. I think there are two drawbacks to this setup. First, .380 ammo is damn expensive - much more than 9mm. Second, the mags are a pain to load. I was using the converted Madsen mag that barrelxchange sent me. It's a single feed position magazine so it's a pain. I did not try using a standard 9mm UZI magazine and will probably try it next time, but I'm doubtful that it will work. You can shove the .380 rounds into the mag but I think they're going to sit too low to feed properly.
It's a fun little conversion but definitely a specialty item that will only appeal to a few people. If anyone is interested in one of these conversion you can contact Barrelexchange and discuss it. He also talked about a .380 conversion for the Micro. I tried a .380 barrel in my closed bolt Micro and found that it didn't have enough power to cycle the bolt. Because of the cutout in the top of a Micro bolt, it would not be easy to make a lightweight open bolt.
Barrelxchange then sent me a lighter bolt. He used one of his 9mm heavy bolts and made an aluminum top to it instead of tungsten. The internal holes were left empty instead of inserting the tungsten cylinders. I tried that bolt with a standard Mini UZI spring and it still was not ejecting strong enough to be reliable, however when I switched to a weaker spring, the setup ran 100%. The spring I used was the spring from a full size UZI. I cut off the forward end of the guide rod so I could remove the spring and then cut the spring so the free length (uncompressed) was 8".
It proved to be a lot of fun to shoot. With that spring and bolt it had a pretty slow ROF. Plus the light recoil of the .380 made it easy to keep the gun dead steady. I think there are two drawbacks to this setup. First, .380 ammo is damn expensive - much more than 9mm. Second, the mags are a pain to load. I was using the converted Madsen mag that barrelxchange sent me. It's a single feed position magazine so it's a pain. I did not try using a standard 9mm UZI magazine and will probably try it next time, but I'm doubtful that it will work. You can shove the .380 rounds into the mag but I think they're going to sit too low to feed properly.
It's a fun little conversion but definitely a specialty item that will only appeal to a few people. If anyone is interested in one of these conversion you can contact Barrelexchange and discuss it. He also talked about a .380 conversion for the Micro. I tried a .380 barrel in my closed bolt Micro and found that it didn't have enough power to cycle the bolt. Because of the cutout in the top of a Micro bolt, it would not be easy to make a lightweight open bolt.