The following is all I know on this subject.
In marine corp boot camp in 1960 I was issued a brand new IH Garand. We did not get M14 until 1965. At the range I could not qualify and I tried very hard with a DI screaming he was going to kill me. He finally tried my rifle, looked at it and said IH should stick to tractors. He got me a very used springfield, pitted barrel and I shot expert everytime we fired for qualifaction as long as I had this rifle.