Were US Navy soldiers issued weapons in WW2?
Well, members of the Navy are not called soldiers, but sailors. Navy ships do have an armory that contains small arms: rifles, shotguns, and pistols. The weapons are not issued to each sailor individually. When weapons are issued, they must be returned. There were M1 Garand rifles one ships during the Second World War. However, your great uncle may have acquired the rifle some other way, hopefully not illegally.