FGR Academy graduate McGrory is in his second year as a full time professional at The New Lawn and spent time on loan at Evesham United and Aldershot Town last season.
Louis has been training with the squad and is in line to make his debut this coming weekend when the Crusaders face an away trip to Margate.
Bobby Wilkinson is delighted with this latest addition to his squad and a warm welcome to Louis from everyone at Hungerford.