I am reading Miracle at Belleau Wood: The Birth of the Modern U.S. Marine Corps by Alan Axelrod. Before and during World War I the Marines were known for training often with their rifles compared to other services. Several diaries and letters from the German soldiers who fought against the Marines at Belleau Wood commented on the "sustained and accurate rifle fire" from Marines as well as a statement that they "killed everything that moved".
This is where the Marines got the label "Devil Dogs" (Teufelhunden)
At that time the Marines got a few extra bucks in their pay based on their rifle marksmanship rating. It may not seem like much today but it was an incentive to practice, to learn, to develop better shooting skills.
There was supposed to be 800 yds. between the Marines and the Germans that day (across a wheat field). When the Germans came out of the woods to cross that wheat field the Marines began to kill them. The Germans attempted to attack across that 800 yds. several times before losing so many men they could no longer make attempts. The gave up and reported back to their command that they were facing a battalion of snipers.
The Marines were using 03 Springfields with issue ball ammo. Nothing special. No match ammo, no special sights, no bedded actions, just US Marines and their rifles.
RIFLEMEN...God love 'em