Optional upgrade that makes a tremendous difference in accuracy beyond 70 feet and is adjustable to allow for fine tuning to different dart types.

This is a sleeker, chunkier, and more durable SCAR barrel option for the Nerf Caliburn as well as other higher-powered Spring Nerf Blasters. 

The length of the venting section can be easily adjusted 2-inches by unscrewing the two halves, then using the included jam nut to lock the new length setting. Once strung the screw feature can be used again to adjust the twist (setting the inner effective ID of the strings) and then locked again with the jam nut.

Once dialed in as desired the whole assembly can be protected with the optional length of polycarbonate tubing.

SCAR device attaches to the outer diameter of the blaster using three 4-40 screws as clamps. Included three fishing line terminal blocks to aid the stringing process. Also includes the spool of fishing line.

Assembly instructions: http://captainslug.com/nerf/SCAR%20Assembly%20Instructions.pdf