Quick update. I usually buy MDT mags during their Black Friday sale. I just received the ones I ordered for this sale. The recent metal 12 round AICS mags I just received are different than the previous ones. If your MDT mag has the 3 indented lines on the sides then it won’t fit in the tac A1. The newer ones with the 5 indented lines on the sides, do fit.
Couple of caveats here. First trying to remove them is a pain. They don’t drop free and you have to move it around while pulling down and hitting the mag release. Also I didn’t confirm if they would feed, cycle and eject a round in the Tikka tac A1. So that’s still an unknown.
Interestingly enough the polymer mags with the metal feed lips are the same design as the one I previously tested. So no change there and those worked. Although the mag rekease was also not very smooth.