The M-14 is really just a revamped and improved M-1. The barrel
diameter was changed from .30 caliber to 7.62 mm in order to accomodate
NATO ammunition standards. The breech-loaded 8-round clip was replaced
with a bottom-loading 20-round magazine. And the bolt release mechanism
was changed so that you no longer had to stick your thumb into the
breech in order to release the bolt during inspections, thus removing
the greatest hazard related to use the M-1: "M-1 Thumb." In all other
respects, the M-14 is pretty much that old WWII rifle, the M-1. Unlike
the early versions of the M-16, both the M-1 and the M-14 were
remarkably durable and dependable weapons.
Bill Ehrhart