I have a factory built Armscorp M14NM (semi auto) all USGI. I intend to dabble in heavy metal with it, but am having trouble. The spring guide seems to be binding causing it to be nearly impossible at times to put a mag in with the bolt open.
I've taken it apart and lubed it up, which helps, but more often than not, can hardly get the mag inserted.
Is this a common problem? Any quick fixes?