"Marines still using 1903 springfields in the south pacific stole crateloads of M1 Garands from Army supply depots."
I hadn't heard that and wonder about the source. Soldiers and Marines going into action in the PTO carried their rifles; the action was island hopping and depots were non-existent anywhere near the front, the closest being Hawaii and later Australia. Also, in only a few places were Marines and Army in the same area at the same time. I have heard of Marines on Guadalcanal being relieved by soldiers swapping their '03's for Army M1's but a unit armed with the 03 would not receive ammo packed in M1 clips or vice versa, so such swaps might not be too useful.