"Why didn't the assasins choose .50 caliber rifles if they're so great for assasinations?" They have only been around since the late 80 or early 90s. Although the marines used a scoped and modified ma duece in vietam.
I was in the Marines from '66-'68 - only 50 calibers I saw were truck mounted; hardly shoulder weapons....the bullets alone are damn near 5 inches long. Would you clarify for me?