Hey guys, I'm new to the AR life. I recently bought a Hardened Arms upper receiver and 15" quad. All fits excellent and looks great. However, the barrel is touching the top of the end cap. Not sure why, I had local gunsmith put both components on the M&P.. Any suggestions as to why the barrel wouldn't be center of end cap and is it an issue or problem that needs to be corrected? Thanks in advance!

If it is supposed to be free floated and is touching the end cap your gunsmith needs to fix it. It will cause fliers.