Pretty dumb observation question

WhoAmI

Private
Minuteman
Jan 21, 2014
21
0
Idaho
a pretty brain dead question so please don't hate I was wondering what the small front site on military sniper rifles is for is it just a marker so they know where the top and center of the barrel is when machining or does it have a purpose ? Iv seen them on like top sniper and shows like it and on the member here named delta 3/4 profile pic and was curious