You would be further ahead to look at something like the V-Bull Precision Mag conversion which uses A.I. mags......this system is tried and proven......
There were problems with the M14 mag system on bolt guns......mostly feed related......Robar Industries tried this back in early 1990's.......It was ridiculously expensive $600.00+ U.S. for the conversion......AFAIK, Rober no longer offers this conversion.
Plus the M14 Mag is for a Semi Auto, so it is limited to 5 rounds regardless of being used in a bolt gun.........unless the mag is permanently modified so that it will not function in an M14/M1A.......