Recruits are introduced to the four shooting positions during Grass Week, training days 30-34.
A Combat Marksmanship Instructor, or CMI, teaches recruits the fundamentals of weapons safety and marksmanship with their M-16A2 service rifle.
During this week, recruits become familiar with the following shooting positions:
Recruits learn how to fire, how to adjust their sights and how to take into account the effects of wind and weather. They spend hours in the four positions, preparing their bodies to remain steady while they shoot.
Recruits will also “zero” their service rifle and fire a grouping exercise to verify how their individual rifle shoots. The results will tell the recruit the initial sight settings.
By the time a recruit fires that first actual shot during Firing Week, he or she will have dry-fired his or her rifle from each of the four positions thousands of times.
Above information found on the Parris Island web site, July, 2009.