Slickside upper with attached diopter front sight 
Based off of the Lafrance industries M16k upper receiver. 
Orignal diopters were welded aluminum tubes.  ours are machined front sights attached by aluminum dip brazing. 
 
An early crude CQC/PDW design.  
The front sight is completely non adjustable and was designed for point and shoot tactics.
 
If it shoots high, aim low.
If it shoots low, aim high. 
 
This upper receiver may not be compatible with all optic mounts, without modification. 
 
Black anodized uppers in stock!