01-30-2023, 02:55 AM
Explain won't feed rounds from magazine. Are you able to chamber a round and eject it by hand with out a problem? What type of barrel and bolt do you have? Does your upper fit the lower OK? Does the barrel feed ramps look OK in the upper? What type of magazine are you using? Is the gas tube old-new-fit the gas key properly? The Colt carrier was an older anti full auto type to prevent the rifle from tripping an auto sear.. Did you try using both lowers on your Grendel upper? Need more info..