The Marine Corps conducted a Service Rifle trial concluding in December 1940, according to General Julian Hatcher's "Book of the Garand."
Test along with the M1903 Springfield were the Garand, a Winchester Semi-Auto, and the Pedersen rifle. The Marine Corps Officially selected the M1903 Springfield, while noting that the Garand was the best of the semi-autos.
The Marine brass were as completely hidebound as this appear. Most European Armies also shied away from the use of semiautomatic service rifles, the thinking being that they would result in prodigal ammo expenditure and were too complicated to be reliable.
The Navy and Marines even declined to contribute any funding to the development of the M1 prototype rifles, or "tool shop" rifles, though a few thousand dollars would have resulted in a much large quantity being built. So the Arsenal system duly set about tooling up to produce additional M1903 Springfields in support of the Marine Corps decision.
Anocedotes about the Garand were quoted by Hatcher, and others, from Marine Major J. George's book "Shots fired in Anger." Major George recounted how an Army patrol, accompanied by some of the Marines being relieved on Quadalcanal, were ambushed and opened up with their Garands. The Japanese apparently fled, and a few days later communications intercepts noted that new units had arrived on Quadalcanal "in which every man had a machine gun."
Major George also recounts the story of another patrol of how a Marine followed a GI closely, so that he could snatch up his Garand. Pressure by Marine grunts made the brass reconsider their decision. Marine Raiders were also equipped with Garands in part(Merritt Edson, as a distinguished marksman had been on the committee) and also reported tying them down with wire so that they would not be stolen.
The Marine Corps complained bitterly throughout the rest of the war that they were being given short shrift in delivery of M1's, although there is no evidence to support it. One result was that most servicemen were trained with M1903 Springfields, then issued Garands in theater.
It is wondrous that the poor Marines Corps was able to develop their own pixel camoflage uniforms despite being so impecunious. Army officers also tell their troops they're poor. Try telling soldiers you have budget to spend, and you get Special Forces travel vouchers!