The Firing Line Forums - View Single Post - Does this bug you as much as it does me ?

jcj54 · January 13, 2020, 11:53 AM

If you hold the receiver in a vise block and loosen the barrel nut and put an angle finder on the top of the receiver and then put it on top of the front sight ears you should be able to rotate the barrel assmbly until the angle reading are a close match. Then carefully tighten the barrel nut taking care not to rotate the barrel assembly.
I have found that there is usually a bit of clearance between the pin in the barrel extension and the slot in the upper.

January 13, 2020, 11:53 AM	#16
jcj54 Senior Member Join Date: February 28, 2011 Posts: 218	Seen this before If you hold the receiver in a vise block and loosen the barrel nut and put an angle finder on the top of the receiver and then put it on top of the front sight ears you should be able to rotate the barrel assmbly until the angle reading are a close match. Then carefully tighten the barrel nut taking care not to rotate the barrel assembly. I have found that there is usually a bit of clearance between the pin in the barrel extension and the slot in the upper.