The set screw is aligns with and threads through the body of the mount into the QD socket hole in the bottom of the AR-556 gas block.
Using the included 3/8" allen key, the mount is secured for a rock solid mounting with zero movement.
REGARDING THE UPWARD ANGLE OF THE MOUNT:
Being designed primarily for Close Quarter Battle situations, all of our mounts are specifically designed and intended to have, a slightly upward angle of about 5 to 10 degrees when correctly installed.
This angle is a functional necessity of the design to allow for the correct alignment of the sights to be nearest the center of the light beam at 15 to 20 yards.
The angle may vary slightly, due to variances in manufacturing of the gas block and integral lug.
This alignment was tested using the SureFire X200A the X300, Streamlight TLR-1 and TLR-2, and the Insight M3 and M6 Tactical Illuminators.
It should be correct for most quality manufactured lights & lasers.
This incorporated angle also allows for an easier and correct centering and zeroing of a laser such as on the Streamlight TLR2 or Insight M6.
If the mount remains parallel with the barrel, ANY laser mounted on the BLAM will not have enough vertical adjustment align the dot with the sights.
If it is mounted parallel with the barrel, the light will be too low on the target, below center of mass.
