They look like hand guards for a .30 Carbine. There were several variants made during WWII. Also some of the Plainfield models, and some of the transitional Iver Johnson carbines had hand guards that looked like those. They were easier to carve out of wood, and cheaper to produce. Some did have metal perforated hand guards though they were the early models made with surplus parts, and later models made went back to metal on some of the models.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.