11-22-2012, 03:08 AM
I can clearly see one of your problems immediately:
Liberty used a rifle barrel extension, and your upper is an M4 upper. There is a beginning to the feed ramp machined in the M4-style upper receivers, which need a corresponding M4 barrel extension. Your barrel extension can be blended to match your upper, so it's not a huge fix. I've done it before.
![[Image: gallery_18313_138_71257.jpg]](http://www.ar15armory.com/forums/uploads/1315930128/gallery_18313_138_71257.jpg)
Liberty used a rifle barrel extension, and your upper is an M4 upper. There is a beginning to the feed ramp machined in the M4-style upper receivers, which need a corresponding M4 barrel extension. Your barrel extension can be blended to match your upper, so it's not a huge fix. I've done it before.