I recently finished up a Merkel 147E 12 bore. Owner shoots steel through it exclusively. Not the crazy fast stuff either, “mild steel load”. He was very surprised when I told him his gun was off the face and then proceeded to push feeler gauge after feeler gauge through the gap. Merkels are tough guns. They use great steel, have ample locking surfaces. Steel loads are just harsh. Your AyA will come off the face fairly quickly with the use of steel loads. They simply aren’t as strong as a Merkel, nor are they fitted up as precisely as a Merkel.

Is your AyA made up as a wild fowling piece or a game gun? Heavy action? Thick barrels?

The recoil on most steel loads (even mild ones) is pretty significant. Hopefully your stock will be able to also take the heavy repeated jolts a steel load provides. Keep an eye on that too.