With only a little bit if horse trading I have managed to acquire a unique 9mm AR upper. It has a number of features I have never seen in a pistol caliber AR before.
To start with the mag block is very simple. It is basically just a machined aluminum block that slides into the back of the mag well and is held in place by the AR mag release. This mag block takes uodified sten mags which is great as I have a bunch of those. While the mag fit is a bit sloppy, the thing seems to feed no matter how the mag is positioned.
The bolt is also quite different from others I have seen. It has an extra weight inserted into the tail as usual but there is actually a bolt inserted into the front end of the carrier just like the 223 version. The difference being that this bolt doesn't move. It is held in place with the same removable pin as its standard cousin. Because the bolt doesn't move, it cannot be removed from the carrier without unbolting the gas key. The bolt has no lugs and is cone shaped. It matches the cone shaped barrel extension.
The ejector is not part of the mag block. Instead it is a spring loaded pin that is mounted on a cross pin inserted in the lower edge of the upper receiver. This makes the upper specific to this application while the ejector is installed. It would be simple to push out the pin and remove the ejector which would allow the upper to be returned to use with a rifle caliber.
Currently the upper is an A1 carry handle version. Eventually I'd like to swap to a flat top upperwhuch will require the ejector pin hole to be drilled. Not a big deal with the right equipment.
The barrel is about 11" long with a surprisingly heavy profile. It had a long,nasty ported brake installed which I promptly threw away. The front sight base has the stub of a gas tube protruding out of it. Not sure why that was installed and then cut off. It had a set of plastic CAR Handguards on it but I plan to replace those with a free float rail.
To start with the mag block is very simple. It is basically just a machined aluminum block that slides into the back of the mag well and is held in place by the AR mag release. This mag block takes uodified sten mags which is great as I have a bunch of those. While the mag fit is a bit sloppy, the thing seems to feed no matter how the mag is positioned.
The bolt is also quite different from others I have seen. It has an extra weight inserted into the tail as usual but there is actually a bolt inserted into the front end of the carrier just like the 223 version. The difference being that this bolt doesn't move. It is held in place with the same removable pin as its standard cousin. Because the bolt doesn't move, it cannot be removed from the carrier without unbolting the gas key. The bolt has no lugs and is cone shaped. It matches the cone shaped barrel extension.
The ejector is not part of the mag block. Instead it is a spring loaded pin that is mounted on a cross pin inserted in the lower edge of the upper receiver. This makes the upper specific to this application while the ejector is installed. It would be simple to push out the pin and remove the ejector which would allow the upper to be returned to use with a rifle caliber.
Currently the upper is an A1 carry handle version. Eventually I'd like to swap to a flat top upperwhuch will require the ejector pin hole to be drilled. Not a big deal with the right equipment.
The barrel is about 11" long with a surprisingly heavy profile. It had a long,nasty ported brake installed which I promptly threw away. The front sight base has the stub of a gas tube protruding out of it. Not sure why that was installed and then cut off. It had a set of plastic CAR Handguards on it but I plan to replace those with a free float rail.
