Analyzing the ejection pattern is one of the methods of determining whether or not a M1icon is performing properly.
If you have a weak op rod spring, bolt velocity is increased and the ejection becomes more violent and less uniform. A well tuned M1 should "pile them up" in about a 24" circle when fired from prone on grass or other surface where the brass lays where it lands.
This of course is with either USGI M2 or M72 ammo or equivalent hand loads. Other factors also contribute such as a good straight well fit op rod that doesn't drag wood. (you would be surprised how many do)