05-10-2011, 03:10 AM
It might be the upper. Does it have M4 feed ramps? If you aren't sure what to look for check here: http://upload.bayoushooter.com/images/rs...8z9uev.jpg
You can do this yourself with a dremel tool if you are careful, the aluminum in the upper is soft compared to the barrel extension.
You can do this yourself with a dremel tool if you are careful, the aluminum in the upper is soft compared to the barrel extension.
