As illustrated here in this wonderful photo captured by Daz’s Photography, French soldats only ever carried their muskets on their left shoulder, whether at the “portez” or “au bras” positions. By contrast, a French Officer or “bas Officier”, a supernumerary NCO such as a sergent or a caporal acting as a sergent, always carried their musket in the right arm and with the bayonet fixed.
Our British followers might recognise this position as the “advance arms”, but the French army never adopted this position for soldats, even through and after the Napoleonic wars.
Le Régiment Gatinois 