In November 1942 she was switched to duty with the convoys to the Soviet Union, protecting merchant shipping delivering vital supplies to Russia for her war against Nazi Germany.

This was a role that Musketeer was to perform for most of her wartime service, although from May to September 1943, following a refit, she once again served in the Home Fleet guarding the Western Approaches.

On 25 February 1944 Musketeer was involved in a collision with the Polish destroyer ORP Błyskawica, breaking off from convoy duty to be taken in hand for repair by Brigham and Cowan shipyard in Hull.

Following VE day in May 1945 Musketeer continued her service in the Mediterranean and helped in the support of the garrisons in Trieste and mainland Greece.

In the early 1950s, it was proposed to convert the five remaining ships of the M class, together with seven War Emergency Programme destroyers to Type 62 Air Direction Frigates.