Great gun maintenance tool - Midwest Industries Upper Receiver Rod

This not not a cleaning tool. The tool is used to prevent torque damage to your upper receiver while installing or removing muzzle devices and barrel nuts should they be stuck. The tool is inserted into the upper receiver after removing the bolt carrier group and charging handle. The spline at the end of the tool fits into the barrel extension to prevent the barrel from rotating. The opposite end of the tool is held in a vise allowing you to work on your firearm. It also acts as a go no-go tool to ensure your barrel extension is properly timed (aligned). I had recently bought a new complete upper and went to replace the standard A2 flash hider. The tool spline would not fit into the barrel extension. This improper barrel extension installation would have caused damage to the lugs on the bolt and barrel extension since the lugs of the bolt and barrel extension would strike each other every time the bolt cycles (which is not normal).