If the magazine is a M-14 magazine modified to be used with the stock unit, I fear it would have to be pinned at 5 rounds.
If it is an M-14 type rifle manufactured for the stock unit, it should be OK, however.....
If there is a little square hole in the front wall of the magazine box, I think it is doomed.
If it doesn't have the little square hole, and if it doesn't work in a M-14, it will be fine as a bolt action rifle magazine.
The AIA rifle was designed around the M-14 magazine. To keep them from being limited to 5 rounds, the magazine was redesigned, modified slightly and newly manufactured.
I don't think that a M-14 two position feed magazine will fit the opening in the bottom of a Remington receiver, thus the single position feed arrangement.
Incidentally with all the M-14 owners salivating at the possibility of a legal 20 round magazine for their M-14s, this discussion is very likely going to result in a very detailed examination of these magazines by the powers that be.
Any bets on their interpretation?